How To: Make a new boot disk for your HP 4145B Semiconductor Parameter Analyzer. - Page 1
Forum section: electronics / repair

author: TERRA Operative
author_rank: Super Contributor
timestamp: January 13, 2022, 03:51:01 pm
content: Ok, so I figured out the process of making your own 4145B Boot Disk using info from around the web etc, so I thought I'd document it here for posterity and to help anyone else who needs it.First up you'll need a couple things:- PC with 3.5" floppy disk drive (ThisMUSTbe directly connected to the motherboard, USB disk drives WILL NOT work due to the low level access required).- A 3.5" floppy disk, HD is fine, we'll reformat it as needed later.- A CD and CD/DVD burner.- The attached CD .iso file.Unfortunately I don't have an old PC that supports USB boot, so I currently can't make instructions for that, check here for USB boot instructions:https://torlus.com/floppy/forum/viewtopic.php?p=24043&sid=90a698af4dbda5c4568c26813d8da371#p24043If anyone makes a disk using a bootable USB key, feel free to document the exact process in this thread.First up, you'll need to burn the attached disk image to CD. Any software (even late versions of Windows can do it) that can burn a .iso file is fine.Boot the PC with the boot CD, you will be greeted with a command prompt at drive A:Put some tape over the hole in the top corner of the 3.5" disk (Opposite side to the movable write protect window) to tell the disk drive that the disk is a Double Density (DD) disk instead of a High-Density (HD) disk.With the 3.5" disk in the disk drive, type 'FORMAT B: /T:80 /N:9' to correctly format the disk as a DD 720K disk. (Substitute your disk drive letter if needed).Don't set a Volume label, you can also format as many disks as you need one after the other here.Once the disk drive has finished buzzing and groaning and your disk is formatted, type 'R:\IMGDISK\IMD' to select the R: drive to access the Image Disk files on the CD and start the Image Disk software.Hit the 'ESC' key to close the intro screen and then press the 'S' key at the main menu page of Image Disk to set the following settings:Drive: A (Try other letters if it doesn't work for some reason)Cylinders: 83Sides: OneDouble-step: OffR/W gap: CalculatedFormat gap: CalculatedFormat Fill: E5Full analysis: NoInterleave: Best GuessRetries: 5Keep bad sector: No500kbps -> 500kbps300kbps -> 300kbps250kbps -> 250kbpsPress 'ESC' to escape back to the main menu, then press 'W' to select the disk image to write.Delete 'A:\' in the file selection field and type 'R:\', then hit 'ENTER'. Hit 'ENTER' on 'IMGDSK\' then press left key and hit 'ENTER' on '4145BDSK' to select the disk image.Folow the screen prompts and wait a few minutes until it's finished and then go boot your 4145B!

author: RikV
author_rank: Regular Contributor
timestamp: August 12, 2024, 01:22:36 pm
content: Well I could not resist. A 4145B for a reasonable price!Error M02 sounds scary at first but in fact must be one of the easier messages on this thing. Of course there was no system floppy with it. Closer inspection revealed the FDD was mechanically stuck. No problem, disassemble, clean and grease. Now it works -mecanically- as espected.But then one needs a floppy! Some years ago I got rid of most of these and most CD-DVD stuff, keeping a "strategical" supply. Unfortunately I kept no DS/DD variants, only HD. However, HD should not be a problem when properly formatted?I followed your "manual" and produced a boot-CD. Works fine!Then I tried to format a HD as an DD disk on the only machine with internal FDD I have left: Compaq laptop running WIN95. Trying to format with 'FORMAT A: /T:80 /N:9' result in message "parameters not supported". So no re-format, but I believe these parameters are the standard values for DOS? And my disks are preformatted.Next step: disk image tool.Modify the parameters as indicated, write floppy. Successfull!Last step: wait a few minutes until it's finished and then go boot your 4145B!Elas! A lot of terrible noises coming from the FDD and Error mssage M19!Tried thi with different disks: sam result. Also tried to format the disk with the tool. You NEED to enter a value for the 'interleave' parameter (1-90), I used the proposed 43. No difference.Anyone any suggestions on what I am doing wrong? (or is my FDD gone forever?)

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 12, 2024, 01:55:52 pm
content: How far have you disassembled the FDD?If you remove the head moving stepper motor or the track 0 sensor(sometimes integrated with the control board), you will need to readjust it. It is very complicated.

author: RikV
author_rank: Regular Contributor
timestamp: August 12, 2024, 02:08:24 pm
content: I only removed the FDD receiving mechanics: the two parts where you slide the floppy in and that at the end flips down to engage the heads on the disk. I did not touch the heads nor their transport mechanism.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 12, 2024, 03:03:28 pm
content: Hmmm. Not sure about the disk drive beyond a general clean and lubrication, diving too deep is a painful experience as squadchannel mentioned...I'd make sure all the old grease is cleaned out and replaced, without disturbing the heads or sensors....PM me. I'll boot up my 4145B and use it to make a couple disk copies if you like (I have a stack of spare HD disks which work in the disk drive in my 4145B). I can post it to you, it shouldn't cost much for a couple disks.

author: picburner
author_rank: Frequent Contributor
timestamp: August 12, 2024, 03:22:21 pm
content: There may also be alignment differences between the two drives you used that are preventing the floppy disc from being read.I got rid of the floppy disk hassle forever by replacing the drive with a floppy emulator.The procedure to follow is explained onthis forum, you can also find there the version 1.2 of the 4145B software that I posted some time ago.

author: RikV
author_rank: Regular Contributor
timestamp: August 12, 2024, 04:09:36 pm
content: Once I am sure the device is fully working in specs I intend to replace that mechanical mass memory. What I need right now is a known functioning floppy to eliminate a faulty FDD. I gues it is not possible to replace it by an old PC-drive (apart from the separate power supply)?

author: RikV
author_rank: Regular Contributor
timestamp: August 12, 2024, 04:10:59 pm
content: Thanks for the offer! I sent you a PM.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 12, 2024, 04:19:46 pm
content: Quote from: picburner on August 12, 2024, 03:22:21 pmI have been thinking of doing this conversion for a while too.How does it work with transferring files to a PC? Do you just plug the SD card into a card reader and read the contents directly on the PC, or do you need special software on the PC to read it?

author: picburner
author_rank: Frequent Contributor
timestamp: August 12, 2024, 04:34:02 pm
content: If the file already exists (and in this case it already exists), you can copy it and read it normally from the SD card with any PC.To create it from scratch, however, you need a software.It's all explained on the manufacturer's website.

author: picburner
author_rank: Frequent Contributor
timestamp: August 12, 2024, 04:44:26 pm
content: Quote from: RikV on August 12, 2024, 04:09:36 pmThe 4145B drive spins at 600 rpm, a normal PC drive spins at 300 rpm. So no, you cannot replace it.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 13, 2024, 01:04:27 am
content: Quote from: picburner on August 12, 2024, 04:34:02 pmWhat I would love is a solution that allows me to just drop a program etc that I write on my PC to an SD card or USB stick etc and then plug into the adapter on the instrument to read like a floppy disk.I could just control the instrument via GPIB, but that's a whole other thing, which may or may not end up the right way to go, I'll have to get my instrument all set up first. Once I clear enough bench space.....

author: the Chris
author_rank: Regular Contributor
timestamp: August 13, 2024, 07:04:44 am
content: If you consider operating via GPIB, there is a tool called SweepMe which offers support for the HP 4145 out of the box (https://sweep-me.net/device/71/HP_4145). I am using it already for some while now and thanks to its sequencer, it is quite powerful for creating test setups which include multiple instruments.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 13, 2024, 01:48:29 pm
content: Oh nice, I'll check it out.I saw this one, but the 'request quote' is a bit unnerving when thinking about how much it will cost......https://www.metricstech.com/product/metrics-win4145/

author: picburner
author_rank: Frequent Contributor
timestamp: August 14, 2024, 05:50:22 am
content: We're going slightly OT but there is also this software made for the 4145A, but it also works with the 4145B. It is written in Python and is a bit basic, but if you are comfortable with Python language, it is open to improvement.The website page I downloaded it from no longer exists but judging by the language it looked like a Polish site.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 21, 2024, 04:40:32 pm
content: Quote from: picburner on August 12, 2024, 04:34:02 pmI just got my hands on an SD HxC Slim emulator as my floppy drive just died a few days ago...(I've just designed an adapter PCB and and getting a set of those made too)Can you provide the DIP switch and config settings you used in yours?

author: picburner
author_rank: Frequent Contributor
timestamp: August 21, 2024, 06:16:41 pm
content: I'll take a shot of my floppy emulator so you can see how the dip switches are configured.I also had to put a resistor because there were problems with the disk-change, I don't remember where I placed it but if you compare the two pcb you can easily find itEdit: ...judging from the soldering, the added resistors appear to be 3: R4, R8 and R9.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 22, 2024, 10:33:18 am
content: Nice! Any specific need for 90R, or will 100R or another similar value work?How did you determine those resistors were needed? I can't find any schematics or other low-level info online...

author: picburner
author_rank: Frequent Contributor
timestamp: August 22, 2024, 12:12:27 pm
content: They are 910 Ohm resistors, I used this value because I have several coils of it, but 1KOhm is fine.These are the pull-up resistors of some floppy-drive lines.

author: RikV
author_rank: Regular Contributor
timestamp: September 06, 2024, 11:07:39 pm
content: Just finished recapping A11,A12,A13,A14,A15 and replaced RAFIs. Have not yet carefuly checked the supply voltages, but it comes alive.Only now I noticed on the DAC board (A4) there are 2 LEDs constantly on! Certainly not a "normal" situation.So, up to the service manual. I've been seeking on all pages and flow diagrams: No sign of A4SD1 or A4SD2.Anyone who knows what error state they indicate. How to solve it? I am not sure about thatus of the LEDs before I recapped, but I guess I would have noticed if they were on... Maybe one of the voltages out of spec after recap?"Problem" solved: SD1 and SD2 are simply connected to the 15V rails!!Why would HPengineers do that? This is a useles and confusing gimmic. All other LEDs are of real diagnostic value, these are just for the show. I think I will remove them..

author: TERRA Operative
author_rank: Super Contributor
timestamp: September 07, 2024, 03:34:29 pm
content: I would check and adjust the power rails as a first step, the golden rule of troubleshooting...Thou shalt check voltages!

author: RikV
author_rank: Regular Contributor
timestamp: September 07, 2024, 10:24:36 pm
content: I did that as soon as I had the opportunity. Right at that moment that was not the case. Anyhow, all voltages were in spec at the time of verification. As I said: the red LEDs are misleading (me), they should be green since they indicate an OK situation.I did some measurements and all SMUs seem operational and rather on spot. Full calibration, starting with the 1345A, to be done (this will take a lot of time I guess).BTW, my 4148B is missing the plastic parts (front bezel and button) of the FDD. Anyone who happens to have the necessary 3D files to print them?

author: physmike81
author_rank: Newbie
timestamp: July 11, 2025, 12:04:19 am
content: Hi,Not sure if anyone is on this thread anymore, but I recently acquired an HP 4145B analyzer; without the boot disk of course. The disk drive also does not seem to be working very well, and I have read through this thread that it is possible to replace the disk drive with an floppy drive emulator that uses an SD card. I would like to try this, but I'm not an engineer (I'm a physicist who knows just enough to be dangerous), and so I have a few questions to help me get started:Where can I get my hands on one of these floppy emulators that I have been reading about here?Is it just a matter of plugging the emulator in to the 4145B, and copying a few files onto the an SD card?Thank you to anyone who can reply to this.

author: picburner
author_rank: Frequent Contributor
timestamp: July 11, 2025, 08:01:42 am
content: You can purchase the floppy emulator in questionhere.This is not a plug-and-play replacement: you will need to build an adapter between the HP 4145B cable and the floppy disk emulator and you will need to build a physical support for it.The software to load onto the SD card can be foundhere, in that forum you can also find some examples of adapters for the floppy emulator.

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 11, 2025, 09:15:03 am
content: I have the setup working, I just have to finalise the design of the adapter board etc.I'll detail the conversion and provide files etc in the next few days.