HP 1653B Floppy modification - Page 1
Forum section: electronics / repair

author: romhunter
author_rank: Regular Contributor
timestamp: June 03, 2017, 05:55:25 pm
content: So, I got this HP 1653B in a very good condition with the price of 200$ (shipping incl.), too bad it doesn't came with the oscilloscope probe, power cable, logic pod or most importantly THE FLOPPY DISK ITSELF. Without it I can't even run the thing. So after countless hour digging in my shelf I found 2 floppy, an old computer with floppy drive and DOS. Also I found on the internet the image file of the disk. So I tried using lifutil to make the disk but meh, floppy just fail.After some time I found out that this guy make it happen by replacing the floppy drive of the 1652B with a floppy emulatorhttp://www.rudiswiki.de/wiki9/HxCFloppyDiskEmulatorI decided to follow his path and no, it doesn't boot up, but got a big delay like it's trying to read somethingAny suggestion? I've already sent an email to the author of that website. Just trying to ask if I should try to modify it or just stop and trying to look for a floppy in vain? And also does anyone else have the same unit as I do? (it's a 1653B) I need to verify if the firmware is the same between 1652B and 1653B.And yeah I know 200$ is a lot but hey, that was when I begin to buy tools, it was kind of a mistake

author: Andy Watson
author_rank: Super Contributor
timestamp: June 03, 2017, 06:14:17 pm
content: Quote from: romhunter on June 03, 2017, 05:55:25 pmDo you know the format of this image? Can it be un-done with lifutil or does require a different process - for example, the IMD format utilities? Have a look at the first hundred bytes of the image file with a hex-editor/hex-dump program and check that it is appropriate.

author: romhunter
author_rank: Regular Contributor
timestamp: June 03, 2017, 06:27:03 pm
content: Quote from: Andy Watson on June 03, 2017, 06:14:17 pmIt's well described in the web page I linked above. The author already did all the task and when he heard that I don't have the disk, he just sent it to me straight away, including the original dump and the .hfe file for use with the gotek emulator (including the modification needed).

author: Andy Watson
author_rank: Super Contributor
timestamp: June 03, 2017, 07:12:11 pm
content: Did you also account for the difference in rotation speed of the HP floppies?

author: romhunter
author_rank: Regular Contributor
timestamp: June 03, 2017, 07:16:26 pm
content: Quote from: Andy Watson on June 03, 2017, 07:12:11 pmyes, and it is also cited in the linkQuotelong story short I have absolutely no idea what went wrong with the drive. Might as well use the LCD tomorrow, since there're 2 LEDs on the drive and only 1 of them light up when power is applied. I think the problem is it doesn't read the emulated floppy although the emulator firmware recognized it... Or maybe not, who know

author: Andy Watson
author_rank: Super Contributor
timestamp: June 03, 2017, 10:43:59 pm
content: Have you tried the emulator on a PC/IBM machine - i.e. without the complication of HP's weird formats?Does the original HP floppy drive still work? - If so, are you aware that "LIF" format floppies have a different format - right down to the sector level? You need software that can interface directly with the floppy disk controller to be able to write/format an HP style floppy.

author: romhunter
author_rank: Regular Contributor
timestamp: June 04, 2017, 01:38:14 am
content: Quote from: Andy Watson on June 03, 2017, 10:43:59 pmI've tried to write a real LIF-formated floppy disk using LIFutil (which is a DOS-based tool) without success since my floppy disk is all dead. I believe that the original floppy drive still work but I don't have a real system diskette to test it. As I said, I buy it without any accessories. I love to see floppy based machine, but hate them when I own them.Also the emulator is hardware-based. I already have the firmware for it to be recognize and function like the original floppy disk drive would (as least that's what I expected from HxC)

author: TAMHAN
author_rank: Frequent Contributor
timestamp: June 08, 2017, 02:37:03 am
content: Ask on the HP Agilent Owners list. A lot of people there, I can even remember sth similar being discussed some time ago.At least, they will have someone who has the disk image and can burn e post you one...

author: romhunter
author_rank: Regular Contributor
timestamp: June 08, 2017, 02:46:07 am
content: Quote from: TAMHAN on June 08, 2017, 02:37:03 amerm.... where can I find it?Quotethat would be great

author: TAMHAN
author_rank: Frequent Contributor
timestamp: June 08, 2017, 03:23:53 am
content: https://groups.yahoo.com/neo/groups/hp_agilent_equipment/Then log in and you should be in.

author: romhunter
author_rank: Regular Contributor
timestamp: July 15, 2017, 02:08:23 pm
content: Just wanna update that it worked using a HP1652B floppy disk. So my theory of those analyzer sharing the same firmware is true

author: Remarkable
author_rank: Newbie
timestamp: October 15, 2018, 07:57:49 pm
content: I was reading this thread as my HP1653B I acquired as an unknown condition without OS system discs University of Oregon surplus sale item for $40 was adamantly reporting the floppy had failed.Even after jumping through all the hoops mentioned here and elsewhere to get a floppy in the right format with the right image - which involved reviving a retired desktop and loading MS-DOS 6.22 onto the not failed drive of the old RAID pair on the box, LIFUTIL finally ran without complaining about track 0. And yet, the floppy drive still sat there grunting at the disk and refusing to load.I had noticed that the mechanism was reluctant to pop out the eject button - I had to push in the disk and jiggle it, and only then would the button slide out and the disk settle in. A bit of contact cleaner made it more responsive, so I assumed grime and accumulation of dust and neglect in the decades since it was new. Maybe even a bit of a spill of a late night Coke during a marathon debug session? Anyway, the disk was now seating properly, eject button pops out adroitly, and still the drive just grunts.Ok, time to get out the TORX bits and take the case apart, lets have a look see at the drive and how to get a replacement in. Drive seems clean and pristine, and shiny and no evidence of corrosion or abuse. However, I also noticed the head carriage was stuck and observing the drive power up, noticed it didn't do the expected home seek jiggle. Hmm. head carriage should slide freely and easily, and gentle encouragement of it when it was trying to move proved ineffective - hell, it wasn't moving at all. A bit of a side-to-side shudder, is the best I could coax out of it. But no linear movement.Get out my handy-dandy picks and pokes and prod around in the slide and linear bearing and it feels a little grungy - the slide rod is not smooth as I expect it to be - it looks clean and pristine, just doesn't feel smooth when I slide my stainless steel feeler over it. Aha - Coke spill got into the drive proper, and sugar coated the slide, and glued it in position, perhaps? So I apply some leverage, and then some more, and then some force, and then I give up and think I will have to go the route of replacing the drive. So then, if this is a broken drive, why not use some brute force? It's a lost cause, anyway. So I give it a last desperate twerk, and the mechanism gummily moves a bit! yay. I apply some contact cleaner and it slides a bit more freely, so I am encouraged. Alas, even with the cleaner and a bit of gentle scraping of the slide rod, which now feels smooth, and I can move the head carriage by hand, the drive still wont move it under it's own power. I can see it trying, and if gently poked, will judder a few mm in one direction or another, but it's still mostly stuck. Sigh... I might have to take the whole drive apart to give the mechanics a good clean in an ultrasonic bath. But also, I have another idea - contact cleaner is designed to clean and wipe and evaporate, so perhaps it was just dissolving the sugar, and allowed the slide to free up momentarily before evaporating and letting the sugar re-gum up the works. So time to try a more invasive option - my LPS-1 lubricant - again, it was a last ditch attempt, and if it ruins the drive then all was already lost, anyway. Of course, its a spray can, and it was late and I was in no mood to go hunting for Q-tips to apply a little to the spot in need - I did use the little red tube to get 'only' the slide mechanism and the head carriage and the optical sensor and the home plate and the base plate a slight dusting of the lubricant. Well, slight dusting is a euphemism dripping with oil... these are pretty small parts, and a drop or two was all I really needed, but, well, it was late.To my delight, the head carriage now moves with ease when I move it by hand, so at least the Coke sugar has definitely been eliminated. I have a concern that the heads are also now coated with the lubricant, as is most of the head carriage. But cleaning the heads I can do later - does the drive at least do the home seeking and motion test? So plug in the cable, power up the instrument, and - YAY - the drive spins, the head carriage moves smoothly to the inside track, and back home. And the screen says , drive - no disc. Brilliant - huge improvement from drive - FAILED. I figure - well, the disc I have been playing with this whole time, I can create a new one and recreate it, might as well pop it in to see what happens. So I do.Disc loads, spins up, heads load, and start to incrementally move inwards - Holy Cow! Screen is showing the olden days equivalent of a spinning hour-glass. It says - Loading System...And then - hallelujah - the setup screen shows up! I whooped, yelped and jumped up and down.A quick run through of the scope shows it is functional, and the state and timing machines are happy, though I have not tested those with actual signals yet. I expect these to be completely functional, as well.Motto - Coke is your friend but not when applied to your analyzer.

author: romhunter
author_rank: Regular Contributor
timestamp: October 16, 2018, 03:54:58 am
content: Quote from: Remarkable on October 15, 2018, 07:57:49 pmGreate motto! And good to see one of those baby back to life.Anyway, would you mind trying out the USB floppy mod? I would love to see another one modded successfully

author: Remarkable
author_rank: Newbie
timestamp: October 16, 2018, 09:43:05 pm
content: I was seriously considering exploring that, and got a bit overwhelmed with the plethora of options and variations I need to wade through - the double speed is one, the single cable connector is another, non-standard motor start and disk load commands apparently issued by the boot rom, and the sorting out what custom firmware tweak and hack I need on the floppy emulator itself. None of it beyond my ability, but right now I can't afford the time... and - it's working already, leave it alone, don't ya know.And I have not seen (I could have missed it...) a 'plug and play' option with a guide of what jumpers to set/remove, and it should just work. If you know of such an option, I'd be happy to procure one and plug it in.Regards,|\/|ark.

author: james_s
author_rank: Super Contributor
timestamp: October 20, 2018, 10:42:04 pm
content: $200 seems like a very high price for a unit that is missing the pods, I got my HP logic analyzer for $25, then the pods and probes were the expensive part and cost me another $150 or so to get a complete set. I forget off hand what model I have but it boots from an internal hard drive, much easier than using a floppy disk.