HP 8594E Replacing the green CRT with LCD - Page 1
Forum section: electronics / projects

author: Miti
author_rank: Super Contributor
timestamp: June 11, 2018, 11:20:44 pm
content: Did anybody try to replace the CRT on the HP8590 series with LCD successfuly? It has a monitor output and NTSC or PAL options but no one seem to be standard resolution. I bought a 5" LCD from ebay and it has CVBS and VGA inputs. It works beautifully from a PC with 640x480 but I can't get it to work acceptably with the SA. The sync signals seem to be totally non standard. Apart from re-clocking it with an FPGA, which may not even work in this case, do you have any idea how to do it? I don't think I can take on an FPGA project. I've attached some sync screen shots for the default sync on SA and VGA 640x480 @ 75Hz.

author: EE-digger
author_rank: Frequent Contributor
timestamp: June 12, 2018, 03:51:46 am
content: You may want to have a look at the GB8220 video converter card. It will take CGA, EGA and other inputs and output at VGA and various resolutions. More importantly, you can adjust timing. It's a bit fussy to set up but you see immediate results from your change of settings.I used it to create a nice 800x600 panel output from oddball sync and separate video from an 8753C network analyzer. I believe I also had it driving a 1024x768 panel.The card is cheap and powerful. Check ebay if you're interested.Like you, this would have been a good FPGA project but no time

author: TheSteve
author_rank: Unknown
timestamp: June 12, 2018, 05:28:06 am
content: I agree with EE-Digger. I used a GBS-8200 to replace the CRT in an 8752C with an LCD. That doesn't mean it will be compatible with an 8594E but it may be worth a shot.

author: Miti
author_rank: Super Contributor
timestamp: June 12, 2018, 10:57:47 am
content: Thanks, that is an interesting board. I see that it doesn't have CVBS input so should I use monitor output to the Y input and leave the PbPr unused? Or maybe go from the internal display connection that has YHV through VGA input connecting all three colors together. It may work.

author: Miti
author_rank: Super Contributor
timestamp: June 12, 2018, 11:10:00 am
content: On ebay, they're all over the place with the description of this board. Pictures combined of a GBS-8220 V3.0 and an HD9820, packing list GBS-8200. How many versions of this board are there?

author: EE-digger
author_rank: Frequent Contributor
timestamp: June 12, 2018, 11:19:51 am
content: I have to apologize. This is the second time I've recommended this board and I just noticed that it does not seem to have a composite input. I used it around 3-5 years ago with RGB inputs and separate sync (to which I had to add a sync separator chip).But I have output my 8596E NTSC video to a Panasonic 5" BW pro video monitor and it gave a nice little image. Yet the same signal input to Sony professional monitors was unable to produce a good picture.I think your scope images sum up the reason for this.What you may want to consider is to strip off the sync, change the timing of it, then recombine with the video. The alternative is to "play", and I do mean play, with some of the composite video to flat panel controller boards.I've been thru several of those and non were shining stars

author: Miti
author_rank: Super Contributor
timestamp: June 16, 2018, 03:37:55 am
content: Don't apologise, it does have YUV though and that should be good enough. Y carries luma and sync and I don't need colour anyway. The output to the CRT module has separate sync so from separate sync, default sync, NTSC and PAL, one must work so I ordered one.I also made some progress using the monitor output. I "discovered" that it has horizontal and vertical position adjustment in the CAL menu. In PAL mode it is almost perfect horizontally but vertically it doesn't fill the display completely but it is usable. In case my green CRT dies, I have a solution. GBS-8220 having size adjustments (I understand) could make things perfect.

author: TheSteve
author_rank: Unknown
timestamp: June 16, 2018, 04:07:50 am
content: The GBS8200 does allow for quite a bit of correction/adjustment. You can change output resolution, adjust location and the size - you might want to order one just to play with.Here is a 1024x768 LCD installed in my HP 8752C network analyzer.

author: Miti
author_rank: Super Contributor
timestamp: June 16, 2018, 10:34:40 am
content: I ordered one yesterday thinking it has YUV input but now looking at some manuals found on the net I think more and more that in this case YUV is the Chinese translation of YPbPr. Do you know if it accepts indeed YUV?

author: Miti
author_rank: Super Contributor
timestamp: June 16, 2018, 03:59:37 pm
content: It gets even better...well, almost. If I reduce the video level with a 1K potentiometer, at one point I get some gradient on the graticule intensity as it should be since the video signal has two levels, high for the trace and markers and lower for everything else. Unfortunately, the video level where this happens is way too low in my opinion.

author: xwarp
author_rank: Frequent Contributor
timestamp: June 20, 2018, 11:21:36 am
content: Quote from: Miti on June 11, 2018, 11:20:44 pmWould you mind sharing, or messaging a link to the display you got?

author: stj
author_rank: Super Contributor
timestamp: June 20, 2018, 01:10:52 pm
content: be carefull not to blow your converter,the gonbes boards dont tolerate TTL sync pulses - max input is about 3v

author: Miti
author_rank: Super Contributor
timestamp: June 23, 2018, 12:40:08 am
content: Quote from: xwarp on June 20, 2018, 11:21:36 amI bought this one:https://www.ebay.com/itm/VGA-AV-LCD-driver-board-and-5inch-ZJ050NA-08C-640X480-LCD-Screen-for-50Pin-TTL/183257271186?hash=item2aaafc0b92:g:k2oAAOSwBPJasOZubut it is a bit small and it doesn't fill the 8594E frame, I will post some pictures. I'm thinking a 5.6" like this one would be better:https://www.ebay.com/itm/VGA-AV-Controller-Driver-Board-kit-with-5-6inch-LCD-Screen-AT056TN52-V3-640x480/153022921644?hash=item23a0e07bac:g:lo8AAOSwD5pa-q6uEdit: Added pictures.

author: Miti
author_rank: Super Contributor
timestamp: June 23, 2018, 12:45:39 am
content: Quote from: stj on June 20, 2018, 01:10:52 pmThanks for the info Stj! How do you know this? I looked through some manuals and I didn't see that.

author: stj
author_rank: Super Contributor
timestamp: June 23, 2018, 11:53:04 am
content: it's a 3.3v chip with no clamping on the inputs.lots of good info here:https://ianstedman.wordpress.com/

author: Miti
author_rank: Super Contributor
timestamp: June 24, 2018, 02:29:08 am
content: Do you know what chip it is?

author: stj
author_rank: Super Contributor
timestamp: June 24, 2018, 10:07:05 am
content: i think it's mentioned at that link.

author: Oldtestgear
author_rank: Regular Contributor
timestamp: July 11, 2018, 07:08:14 pm
content: https://www.ebay.co.uk/itm/VGA-AV-LCD-controller-board-with-5-6inch-640x480-AT056TN52-lcd-panel/251590018265?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649I bought this module a week ago & it arrived today. A very quick hook up suggests that this one may be a good option. Proper testing will take a little longer!Phil

author: Miti
author_rank: Super Contributor
timestamp: July 11, 2018, 11:05:47 pm
content: Quote from: Oldtestgear on July 11, 2018, 07:08:14 pmYes, I was looking at that (or similar) LCD, my 5" is too small. Did you connect it to the monitor output?Could you please do some tests?1. Go through all three video modes, default sync, NTSC and PAL and see if it syncs in all three.2. Try to center the image using the CRT Vert and CRT Horz position in CAL menu. See what the adjustment range is.3. Place the front mask on top of the LCD and post some pictures. I want to see if the image fits inside the mask and if it aligns with the right hand buttons and also if the aspect ratio is correct, if the grid is square.I received my GBS8220 and is not really usable. In YUV mode it only synchronize in NTSC (I think YUV is an NTSC only thing) and passes the signal without processing, meaning that there's no geometry adjustments. IN RGBS it has geometry adjustments but I would have to strip the sync pulses from video and again it only works in NTSC.The problem with it only working in NTSC is that, if by accident you set it in PAL or default sync (whatever that mean), you may have a hard time setting it back to NTSC.

author: Oldtestgear
author_rank: Regular Contributor
timestamp: July 12, 2018, 07:29:40 pm
content: A quick look & I can start to answer your questions.It only works when the SA is set to PAL.The display bezel will need to be trimmed a few mm on each vertical side for the full display to be viewable.The button legends do align well with the buttonsThe hor. & vert. adjustment controls will centre the display correctly.LCD fixing? That is a question for another day. Probably if I ever get the faults in the 3off 8596s & 1off 8593. I got these plus a very large heap of test gear from a company closure & have spent the last 4 months quietly sorting various instruments to keep & sell the excess ( a lot according to my wife has still got to go). I cannot resist the urge to buy any test gear that is interesting & the more there is the better I like the deal.Phil

author: Miti
author_rank: Super Contributor
timestamp: July 12, 2018, 10:21:39 pm
content: Really, the vertical doesn't fit? I was expecting the horizontal. Mine works best on PAL too even though it syncs on NTSC as well.Thanks Phil, I think our best bet would be to recap the CRT module when it fails and readjust it as much as we can.Weird implementation eh? I wonder why did they choose such non standard timing. CGA, EGA, VGA must have been invented already.

author: Oldtestgear
author_rank: Regular Contributor
timestamp: July 13, 2018, 04:03:53 pm
content: Sorry, I was not clear. Trimming the verticals on the bezel increases the horizontal Not sure that recapping the CRT module will solve all my display problems as I have at least one dead CRT. Much more work needed before I need to actually start cutting metal to get the LCD fitted.Phil

author: Miti
author_rank: Super Contributor
timestamp: July 13, 2018, 08:53:23 pm
content: Are you sure the CRT is dead. I repaired three CRT modules, all with dry caps. My CRT has burn marks but is still functional.

author: Oldtestgear
author_rank: Regular Contributor
timestamp: July 14, 2018, 04:49:19 pm
content: One may be the caps failing a it takes a while to actually display anything on the CRT plus the whole image starts very large & unfocussed before settling down to a nice sharp & bright image.The other is a dead CRT unfortunately. Thanks for the suggestion.Phil

author: precaud
author_rank: Frequent Contributor
timestamp: July 14, 2018, 05:21:29 pm
content: I'm having a similar issue with an LCD monitor on the composite video output of my Anritsu MS-420K. The image on the LCD is shifted up and to the right, clipping off the top line of the display. The Super Circuits LCD measures 5.6" diagonal. Sadly, its menu has no adjustments for size or position.I've emailed several sellers of LCD panel+controller combos on eBay, asking if their unit offered those adjustments. They all said no.

author: Miti
author_rank: Super Contributor
timestamp: July 14, 2018, 07:43:04 pm
content: Quote from: Oldtestgear on July 14, 2018, 04:49:19 pmYes, that is typical dry caps symptom. You replace them with some good quality caps and you give it another 10+ years.

author: Miti
author_rank: Super Contributor
timestamp: July 14, 2018, 07:44:58 pm
content: Quote from: precaud on July 14, 2018, 05:21:29 pmWhat about the instrument itself. Does it have horizontal and vertical adjustments like HP8590E series have?

author: precaud
author_rank: Frequent Contributor
timestamp: July 14, 2018, 08:53:49 pm
content: It has them, but unfortunately they don't affect the external composite output, only the internal.

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2019, 02:04:17 am
content: I want to revive this topic. I think I found a reasonable solution from the cost and complexity perspective.After I saw the Simmconn Lab's board (manual attached), I wanted colour. I wanted to find a simple solution to have a green graticule and yellow trace.I know that my 5" AV LCD can synchronise when HP8591E is set to PAL video. I tried to separate the low and high brightness of HP8591 and feed them to green and red of an AD722 encoder, then feed the output CVBS to the LCD. The image is fuzzy and has relatively low resolution while there's colour crawling across the screen that is unacceptable. Screen shot attached.Then I came back to directly driving the LCD from the SA video, I reduced the half brightness of the A16 video output by adding a 390 Ohm resistor in parallel with R301, as described in the same attached manual.I then raised the output black level by about 250mV to make room for the sync pulses and added two transistors for HS and VS.The result is shown in the attached simulation file, just rename the txt to asc.Everything on the left of R13 is on the A16 board. R13 and everything on the right is my circuit.The result is a B&W, very sharp image, with two levels.Pictures and pros and cons in the next post.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 04, 2019, 02:15:40 am
content: What kind of lead length do you have running from one area to another? Do you have a photo of the overview of the connections? The text file is wire here and there. Is that supposed to be a schematic layout? One more thing is there any coaxial running in there or are you doing plain wire. Plain wire is leaky. Coaxial is lossy and needs a DA.

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2019, 02:20:46 am
content: Here are some pictures with the result.Pros:* Cheap, the LCD can be bought on ebay for less than $50 and the rest is peanuts* Not very invasive, you only add a resistor to the A16 board, everything else is external* We have a solution to recover a SA with a dead display. A solution that costs 350 USD, is hard to justify for me.Cons:* No colour or at least green colour (even though it may be a solution. Modify the LCD driver to drive the green colour only, AKA shorting R and B lines to GND)* Does not align perfectly to the plastic frame. The image fills the screen horizontally but it's a bit compressed vertically.* No dimensional control. 5" is a bit small, 5.6"would fit better vertically but would go out of the frame horizontally, by my calculation.

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2019, 02:24:08 am
content: And a picture with the frame and smoky screen.

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2019, 02:27:14 am
content: Quote from: Quarlo Klobrigney on December 04, 2019, 02:15:40 amIt is an LTSpice .asc file. Change the extension to .asc and open it in LTSpice.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 04, 2019, 03:25:14 am
content: I thought this was with something that you were cobbling together that resulted in lack of high frequencies. I am confused.Don't have LT Spice.

author: Miti
author_rank: Super Contributor
timestamp: December 04, 2019, 05:11:06 pm
content: Quote from: Quarlo Klobrigney on December 04, 2019, 03:25:14 amIt’s free software, very useful. You can download it.Or I can take a screenshot and post it later.Edit: Added schematic screenshot.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 04, 2019, 07:17:06 pm
content: As long as they don't need a lot of info and my first born!

author: madao
author_rank: Frequent Contributor
timestamp: December 05, 2019, 08:40:11 am
content: What is typ of display ?Here ?https://www.ebay.de/itm/New-5-6-5-6inch-640-480-TFT-LCD-VGA-RGB-AV-Module-Display/121194129870?hash=item1c37bba9ce:g:sFgAAOxyWt5SW1Sm

author: Miti
author_rank: Super Contributor
timestamp: December 05, 2019, 11:27:12 am
content: Quote from: madao on December 05, 2019, 08:40:11 amThere’s a link to the one that I bought in ones of my previous posts. As I said, 5.6” may go out of the frame horizontally.

author: Miti
author_rank: Super Contributor
timestamp: March 28, 2020, 10:37:40 pm
content: I experimented a bit more with the LCD by manipulating the color bus. The result is, I can make separate colors for the low and high intensity.Below is the result of grounding the low nibble of the red bus and connecting the high nibble to the MSB of the driver through the 4 x 33 Ohm resistors.This way I can have yellow, cyan or magenta grid and menus. Trace is always white.

author: Miti
author_rank: Super Contributor
timestamp: April 18, 2020, 10:41:29 pm
content: New progress. I started playing with an Altera Cyclone 2 FPGA, mainly to improve my Verilog.I don't know how other learn but for me, it's hard to learn without having a real project so I thought why not make something useful and learn in the process.Enough ranting, let me tell you what I found.The development boardI started with playing with an Altera DE1 development board from Terasic. I modified their VGA Verilog example, which was set to output 640x480, to 1024x768 60Hz. Then I started playing with the VGA parameters changing the pixel clock, sync timing, back and front porch, etc.To my surprise, the 5" and 5.6" LCD modules that I bought from ebay are very tolerant with non standard timing, they auto adjust pretty much to almost anything I throw at it... well, within reasonable limits, and where three normal monitors display either "out of range" or an incomplete image.The PAL input signalThe next step was to analyze the PAL, NTSC and DEFAULT sync on my HP8591E and this is what I found. I will only show the PAL specs because that's the one that is of interest at this point, it gives me numbers that I can work with to generate the correct frame rate for VGA.Pixel clock - 21MHzH Sync - 96 pixelsV Sync - 3 linesLine total - 1352 pixelsFrame - 312 linesActive line - by my calculation 508 pixels but it may be 512 pixelsActive lines - 254 linesHorizontal and vertical front and back porch are variable with the vertical and horizontal position.Line time - 64.38usFrame time - 20.087msI also analyzed the two digital circuits that make the two level video output. I named them PIXEL and INTENSITY lines. The PIXEL line goes high every time a pixel is displayed on the CRT, the INTENSITY line stays high if a high intensity pixel is displayed and goes low for low intensity. Scope screen shot attached.The VGA sideOk, so now knowing that the LCD is tolerant to non standard timing, I played with the FPGA PLL with 21MHz input clock to see if I can find any timing combination that would give me the same frame time at the VGA output. And bingo! A pixel clock of 55.125MHz, 1352 pixels and 819 lines gives me the same frame time. These numbers are total numbers, visible is still 1024x768. Why do I want the same frame time? This simplifies a lot the frame buffer size and BOM.I have enough RAM in the Cyclone 2 and up FPGA to implement a half frame, 2 bit, dual port frame-buffer so I don't need external RAM.To reclock the 512x254 PAL image to 1024x768 VGA, I only need to sample, encode and store every pixel (2 bits, pixel and intensity) and then read back and display every PAL pixel to 2 VGA pixels horizontally, and every PAL line to 3 VGA lines vertically. It's up to the LCD driver chip to render the image.The pixel clockAs I said, the PAL pixel clock is 21MHz but I would need to wire it to the FPGA somehow and then generate the 55.125MHz in the FPGA PLL. Another solution is to regenerate it from the H Sync. For that I can use ICS9173B and that is exactly what the Symmconn labs guy is using. Sure his project is much more elaborate, from what I see it accepts all three modes and drives the LCD directly, outputs a VGA, etc, so it must be a real up-converter but I'm not there and I think my solution would work.What do you think about this idea? Any draw backs that you can see? This can translate into a reasonably priced community project to replace the CRTs on these oldies but goldies.I know many think the green CRTs are better but adding a bit of colour for the right price, may be tempting for some.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: April 19, 2020, 09:11:13 am
content: Miti,I think your project is a great idea. The CRT is a big issue on a lot of the older HP/Agilent/Anritsu high end gear.

author: Miti
author_rank: Super Contributor
timestamp: July 26, 2020, 06:24:51 pm
content: A lot happened from my last post. With BIG help from the community, and special thanks to BrianHG, I have the best video genlock circuit to generate the 21(42)MHz video sampling clock and the 55.125MHz VGA clock without any external components, everything is done inside the FPGA.I have figured out how to convert the analog input video with two levels of brightness in a digital two bits, using only two differential inputs.There's also the I2C ADC to read the brightness potentiometer, which I think can be improved/simplified since I don't really care much about linearity, resolution, etc.All these experiments are here:https://www.eevblog.com/forum/projects/modern-equivalent-of-74hc4046-pll/https://www.eevblog.com/forum/fpga/converting-a-two-level-analog-signal-to-two-bits-digital-in-cyclone-iv-orand-v/https://www.eevblog.com/forum/fpga/adc-in-altera-cyclone-fpga/The project continues...

author: Miti
author_rank: Super Contributor
timestamp: August 16, 2020, 03:21:28 pm
content: Almost there, I have to figure out a bug in the code that generates the write address and why a vertical line towards the right side is completely missing.Unfortunately the pictures don't tell the full story. The real thing is way more vivid than the pictures show. The color themes choices are unlimited.

author: BrianHG
author_rank: Super Contributor
timestamp: August 16, 2020, 03:57:57 pm
content: Looks like my 'insane' idea of having an IO pin drive a clock input pin to feed the second FPGA pll works.

author: Miti
author_rank: Super Contributor
timestamp: August 16, 2020, 08:15:10 pm
content: Quote from: BrianHG on August 16, 2020, 03:57:57 pmYes, it does and it saved me a lot of pain, thanks!I can't figure out what is wrong with that line missing on the right side of the image, see those partial characters in the right hand menus. Address is there, wrEN and sample pulse are there, the line is not. And no, it is not the LCD module or the code. All I can think of is that it is the reason why this FPGA is marked EP4CE6 and not EP5CE10. Remember, I'm using an FPGA marked EP4CE6 as EP4CE10 and it mostly work. There must be something wrong with writing to certain addresses.The memory initialization file is displayed correctly though, but I guess there's back door to do that, not through direct addressing.

author: bsdphk
author_rank: Regular Contributor
timestamp: August 16, 2020, 09:06:59 pm
content: If the HP uses a standard CRTC chip, for instance a 6845 or similar, you could also hack the firmware to change the video format.Many HP instruments have undocumented memory read/write commands which would make the process pretty easy.

author: MarkL
author_rank: Unknown
timestamp: August 16, 2020, 10:48:17 pm
content: Quote from: bsdphk on August 16, 2020, 09:06:59 pmHere's an extract from a post on the HP/Agilent/Keysight group. I don't know the address range for the video controller but it can probably be figured out from the schematic...Here are the GPIB commands for the 8590 series:MRDB <addr> - returns single byte in decimalMRD <addr> - returns single word in decimalMBRD <addr>,<count> - returns a block of memory in binary<addr> and <count> are in decimal. The SRAM is 524288 (0x80000) bytes long and starts at 0xf80000. It's a Motorola processor, making storage big-endian. I/O is memory mapped, so there's a lot to explore outside the SRAM range.For write, I found the commands MWRB, MWR, and MBWR. No doubt these are the analogous operations for writing, but I did not experiment with them.For example, the model number exists at 0xffbfee, 16760814 decimal, and is stored as decimal ("spq" below is a local Linux utility that sends a string to the scope's GPIB interface and returns the result):$ spq MRD 167608148595And after that, the next byte:$spq MRDB 167608166969 is decimal for "E" --> "8595E".

author: BrianHG
author_rank: Super Contributor
timestamp: August 20, 2020, 11:42:17 am
content: Quote from: Miti on August 16, 2020, 08:15:10 pmShare your code. A lot of beginners in HDL miss things easily when synchronizing buffers, address counters & data chains and write enables for internal FPGA ram. It gets worse when reading since there is a 2 clock delay from control input to data output.

author: Miti
author_rank: Super Contributor
timestamp: August 20, 2020, 12:51:19 pm
content: Quote from: BrianHG on August 20, 2020, 11:42:17 amIn the end, the issue was in my code. I didn't like it anyway so i rewrote it. See below the result.The only reason why I hesitate posting my code is that "OMG, what a crappy code" anticipated reaction from you, the HDL gurus, which I dread.The new code, even though it (mostly) works, still needs some clean up.Edit: One thing that I found out, it doesn't matter if the frame rates are different between the input and output, I don't see a thing in the image, so I reverted to standard VGA 1024x768 @60Hz (well almost 60Hz, I can't get 65MHz from the output PLL, I get 64.909091MHz but it is close enough). Now I need to make the board.

author: Miti
author_rank: Super Contributor
timestamp: August 24, 2020, 01:05:42 pm
content: One positive side effect of using Brian's idea of digital PLL with DDIOs in the FPGA is that it doesn't need a feedback clock divider as it would if I used MK9173, for example. That means that as long as the HSync pulse is aligned with 4x the 42MHz clock, it would generate the correct 42MHz frequency regardless of the front porch, back porch or active pixels on the line. That means it should work in all 3 video modes that HP8590 can output, NRM, PAL and NTSC. And it does, see below. It's getting better and better.

author: BrianHG
author_rank: Super Contributor
timestamp: August 24, 2020, 09:00:13 pm
content: You are loosing the top few lines in NTSC where the HP logo is and the clock. But, I guess it is to be expected if HP decided just to drop the ~50 missing lines of video instead of having scaled graphics. Otherwise, your LCD panel is dropping those lines out.

author: Miti
author_rank: Super Contributor
timestamp: August 25, 2020, 01:13:19 pm
content: Quote from: BrianHG on August 24, 2020, 09:00:13 pmThat's exactly how it is presented by the instrument, my LCD does not cut anything, see below. Actually there is enough room for the entire image, I don't know why HP decided to cut their logo in half. If my counting is correct, there's only 238 visible lines in NTSC mode, 263 in total with VSync, BP and FP. The clock is there, take a closer look.What's left, is to save and recall the color scheme in/from the EEPROM so it starts with the latest scheme instead of a default one. Since I have the code tested, it shouldn't take me more than 30 min to add and test the module, I just need to find the time and the will.Next step is to make a board, my first board in Kicad, with all the components on the top side (fingers crossed) so it gets assembled by JLCPCB. I don't think two layers is enough but I should be able to place everything on the top layer.

author: Bud
author_rank: Super Contributor
timestamp: August 25, 2020, 02:11:04 pm
content: Quote from: Miti on August 25, 2020, 01:13:19 pmBrianHG is correct, you are missing the top of the screen. HP did not cut their logo. This is what it should look like:

author: Miti
author_rank: Super Contributor
timestamp: August 25, 2020, 02:25:50 pm
content: Quote from: Bud on August 25, 2020, 02:11:04 pmNope, you are not in NTSC mode. What you show me is either NRM or PAL mode. Take a look at my three pictures in the previous page and the picture in this page, which is a screen shot from the CRT.

author: Bud
author_rank: Super Contributor
timestamp: August 25, 2020, 02:52:04 pm
content: Can you see the top on gpib screen capture when in this mode?

author: Miti
author_rank: Super Contributor
timestamp: August 25, 2020, 05:57:20 pm
content: Quote from: Bud on August 25, 2020, 02:52:04 pmGPIB capture does not follow the screen. See below.

author: BrianHG
author_rank: Super Contributor
timestamp: August 25, 2020, 09:16:19 pm
content: Quote from: Miti on August 24, 2020, 01:05:42 pmThe bigger plus is if your sync disappears or is missing, the 42MHz will automatically continue to oscillate at 42MHz as accurate as your system reference crystal oscillator. The other external PLLs would go haywire or produce frequencies which your output graphics would not be able to generate a displayable image from.

author: Tony_G
author_rank: Super Contributor
timestamp: August 25, 2020, 11:04:35 pm
content: Quote from: Miti on August 25, 2020, 02:25:50 pmThis seems to be the part of the manual that Miti is referring to - Used to have one of these but I moved over to an 8563E so I can't provide any more info than this.TonyG

author: Miti
author_rank: Super Contributor
timestamp: August 26, 2020, 12:00:47 pm
content: Quote from: Tony_G on August 25, 2020, 11:04:35 pmThanks TonyG for finding that, I did not read that before, all my posts are based on my observations. Interesting is that I don't see that compression on PAL format, I only see it on NTSC.

author: BrianHG
author_rank: Super Contributor
timestamp: August 26, 2020, 05:22:07 pm
content: In PAL, the lines are there, but they are located in the overscan region. So, on many PAL TVs, that portion of the picture may be off the edge of the screen, but on a monitor, they may still be there.

author: Miti
author_rank: Super Contributor
timestamp: February 23, 2021, 08:05:59 pm
content: Well, it took waaay longer than I expected but Rev 1 boards are here. I just reassigned some pins that were different than my prototype and brought the first one up and it works perfectly. I missed couple of ground connections, nothing that couldn't be fixed with a solder bridge or a wire. I still need to find better, of the shelf connectors/cables in two locations, but other than that seems to work fine. Color scheme can be selected with jumpers or with an IR remote, through the focus adjustment hole.Once I clean up the code a bit, I'll work on an easy mechanical solution to install the adapter and the LCD inside the analyzer.

author: sp9bsl
author_rank: Contributor
timestamp: February 23, 2021, 08:29:39 pm
content: Hello Miti,will you share the project files or is it intended as commercial?

author: Miti
author_rank: Super Contributor
timestamp: February 23, 2021, 08:36:30 pm
content: I would like to put together a kit as a cheaper solution than Simmconn Labs's NewScope-0Jr, which is quite expensive, in my view. Of course, it includes all the HW needed, but many people just want the adapter. I'll see how feasible is to make a kit, or sell as adapter plus cables only.

author: Miti
author_rank: Super Contributor
timestamp: February 23, 2021, 10:58:59 pm
content: Looking at the VGA output, it doesn't look too bad but I wonder if I can improve it a bit by playing with the current strength of the outputs. The current strength is set to "8mA (default)" but there's a "Maximum Current" setting which I cannot find what is anywhere. Do you know what is the maximum current strength of Cyclone?

author: bitseeker
author_rank: Super Contributor
timestamp: November 22, 2021, 10:47:53 pm
content: Hi Miti,Just found your thread. Very interesting project and looks like great results thus far. I was already impressed with the simple B&W version and the color is even better.I have an 8560E and an 8924C, so CRT replacements are in my future and I was curious what the current state of your project is.

author: Miti
author_rank: Super Contributor
timestamp: November 23, 2021, 04:37:26 pm
content: Quote from: bitseeker on November 22, 2021, 10:47:53 pmHi bitseeker, thanks for your interest!My project is on hold right now due to the chip shortage. I can’t find FPGAs at a reasonable price. LCSC has zero stock on almost everything I need. Also some switching regulators are on back order at Digikey.I also have to figure out the mechanical side but I kinda lost interest.However, my adapter is NOT compatible with the 8560 series, it is only compatible with the 8590 series.

author: BrianHG
author_rank: Super Contributor
timestamp: November 23, 2021, 08:43:31 pm
content: Cyclone IV in 256pin BGA are available at a few places like Bristol Electronics. But who knows for how long.The chip shortage will last another 2 years, so be patient.

author: bitseeker
author_rank: Super Contributor
timestamp: November 23, 2021, 11:53:06 pm
content: Quote from: Miti on November 23, 2021, 04:37:26 pmI can understand getting a bit burned out. The chip shortage is a good reason to take a break. It's a very cool project, though, and I totally understand that it's designed specifically for the 8590 series. The project is still inspiring and could be the conceptual basis for bringing new life to other CRT-based equipment, which is why I mentioned a couple of my CRT-based gear as examples.I'm hopeful that projects like this will be able to continue to save our old equipment from the landfill.Quote from: BrianHG on November 23, 2021, 08:43:31 pmYeah, patience is a virtue these days. I don't foresee any of my CRT-based TE burning out in two years, but time will tell.

author: BrianHG
author_rank: Super Contributor
timestamp: November 24, 2021, 12:23:24 am
content: Lattice LFE5U-25F is still available from multiple sources like Digikey, Mouser, Element 14, Farnell..., but, it is overkill for this project even though the price is good. The LFE5U-12F would have been a good fit.But with 1 megabit core memory, you could have very colorful graphics and still cost less than the smallest Cyclone IV.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 24, 2021, 01:52:20 am
content: Quote from: BrianHG on November 24, 2021, 12:23:24 amIt's not available anymore here on Mouser. But if it is elsewhere, good. Overkill but still rather cheap and if available...Note that - as discussed in another thread - the 12F is actually the exact same device as the 25F internally. Except for a device ID number. It's just sold at about 30% to 50% less. Marketing.If you're using Lattice tools, you won't get a full 25F with a 12F, but if you use open-source tools such as yosys/nextpnr you will.

author: BrianHG
author_rank: Super Contributor
timestamp: November 24, 2021, 02:24:19 am
content: Will you look at that, stock:https://www.digikey.com/en/products/detail/lattice-semiconductor-corporation/LFE5U-25F-8BG381C/5358091?s=N4IgjCBcoLQExVAYygFwE4FcCmAaEA9lANogCsIAugL7X4KSkAyAYgKJkCq8FNQAThough its the fastest -8, so the price is high.This chip shortage is like begging for scraps.

author: bitseeker
author_rank: Super Contributor
timestamp: November 24, 2021, 03:39:47 am
content: Quote from: BrianHG on November 24, 2021, 02:24:19 amAnd paying extra for it.However, it's still OK relative to how expensive the commercial LCD-based solution is.

author: Miti
author_rank: Super Contributor
timestamp: December 03, 2022, 01:35:56 pm
content: As an exercise in futility and to prove myself that I'm not bipolar (I read somewhere that starting many projects without finalizing them could be a sign of bipolar disorder... raise your hands those with symptoms, mine is up) I decided to finalize (at least) this project. The 3D printer that I acquired awhile ago and was collecting dust for about a year was put to work and the result is quite good. I made a bracket that holds the LCD, the LCD driver board and my adapter. I also redesigned the front display frame to accommodate a 5.6" LCD module and the different spacing of the buttons menus on the LCD. It also brings some fresh air to the front panel compared to the original dark frame.I've checked again LCSC and Digikey and, to my surprise, most of the parts are available again at reasonable prices and with healthy stock, except for the most important one, the FPGA. Hopefully it will be available soon. With a bit of redesign, some parts are not available anymore in the same package, I think I can revive this project and make it available for those interested. Please enjoy some pictures...

author: Miti
author_rank: Super Contributor
timestamp: December 03, 2022, 01:39:10 pm
content: Some more pictures.

author: jwrodgers
author_rank: Unknown
timestamp: January 17, 2023, 01:30:25 am
content: Hi Miti,Very interesting and great work. Thank you so much for sharing the project you have been working on for so long.I have recently bought an 8590 with a dead CRT screen, and would love to be able to get the hold of one of your converter boards and LCD to go with it. I have a 3d Printer, so could do all the mounting bits.Have you considered making it commercially available, or would you have one or two spare boards that I could purchase from you?Thanks,JR

author: Miti
author_rank: Super Contributor
timestamp: January 17, 2023, 03:04:29 am
content: Quote from: jwrodgers on January 17, 2023, 01:30:25 amYes, I have. Unfortunately for awhile most of the parts were not available anywhere on the planet. At this moment they are back in stock except for the central piece, the FPGA. I have 4 boards in total, 2 Ver.1 with FPGA in TQFP144 package and 2 Ver.3 with BGA. Ver.2 was never built, it added a hole for the power pad of the TQFP but then I moved to BGA package. I could make one Ver.1 available but I'll have to port the code from the BGA to the TQFP (I abandoned the TQFP code after I changed the package but this shouldn't be too hard) and test it thoroughly.PM me to discuss.

author: Miti
author_rank: Super Contributor
timestamp: January 18, 2023, 06:51:02 pm
content: And I was wrong. I’ve checked last night and all the boards are running the latest version of software. I thought I stopped updating the one for the TQFP but I have not. If you decide you want one, I’ll prepare the cables, the resistor you need to solder on the main board and some instructions.

author: jwrodgers
author_rank: Unknown
timestamp: January 22, 2023, 01:39:37 pm
content: Thank you, I'll get a look at it this week and let you know. If it is CRT gone, would love a LCD upgrade for it.

author: Mr. Jack
author_rank: Newbie
timestamp: September 10, 2024, 09:36:07 pm
content: I know it's an older topic at this point, but are these adapter boards still being made?

author: Miti
author_rank: Super Contributor
timestamp: July 23, 2025, 10:55:22 pm
content: Quote from: Mr. Jack on September 10, 2024, 09:36:07 pmI’m sorry, I haven’t followed this thread anymore, there wasn’t much interest in this board. I still have a couple of boards available, pm me if you are interested.Cheers,Miti

author: ce_lab
author_rank: Newbie
timestamp: July 28, 2025, 12:04:53 am
content: I think there may be a lot of interest at the groups.iohttps://groups.io/g/HP-Agilent-Keysight-equipmentI would love to replace the CRT in my 8591E because it's just a matter of time.

author: Miti
author_rank: Super Contributor
timestamp: July 28, 2025, 03:11:03 am
content: Quote from: ce_lab on July 28, 2025, 12:04:53 amI replaced mine 2.5 years ago, even though I've just recapped and adjusted the CRT, and it works great. Bigger, brighter, colors. It gained all those but it also lost that ... vintage personality. PM me if you're interested.Cheers,Miti

author: Miti
author_rank: Super Contributor
timestamp: July 28, 2025, 12:37:26 pm
content: Another improvement to HP8590E series that is worth looking at is replacing the battery backed RAM with FRAM.https://www.eevblog.com/forum/repair/has-anyone-replaced-hp8591(e)-sram-by-fram/100/#lastPost