HP 1650A Logic Analyser

[jwpgroup]

Hi All

I've got the above analyser and, thinking ahead (!), I'm in the process of trying to future-proof myself by converting it to work with a HXC Slim SD emulator before the drive fails (call me a pessimist!)

I've followed, with great interest, the HP4145B thread on here because this analyser uses the same floppy - a MP-F52W-30.

'Skot's postings (and the others contributing there) have been invaluable and I've managed to get the hardware installed OK (I can swap between it and the floppy drive and all is well), but it's the SD disk image files I can't seem to crack (to actually get a booting system).

As far as I'm aware, these analysers use a LIFL disk format and I have the files from the disk (in PC format - supplied by HP to me at some point in the past) together with the HP LIFL DOS utilities (and instructions), as well as the original (83 cylinder?) 3.5" disks (which I can copy on the analyser) which work fine.

I've tried creating a .HFE file of the entire disk (set to 83 tracks as per the 4145B thread) using the HXC utilities but the file is larger than I'd expect and doesn't work. I've also tried making a LIFL disk on a old PC using the HP utilities and the PC files I have, but I can't get that to format a 3.5" DD disk (despite having the correct hardware and following the HP instructions to the letter). I'm currently trying a LIFL hex dump of an analyser disk to see if I can then do something with that.

To be honest, I'm not really sure what I should have in my HXCSDFE.CFG file (I've tried copying Skot's successful one from the HP4145B project and also authoring one of my own) and/or where to go from here. I'm sure the problem here is now down to my lack of in-depth understanding of floppy disks.

Any thoughts gratefully received!

John

[jwpgroup]

OK, well progress (I suppose!) but still nothing working...

I've found the file explanations for .HFE and .CFG and I'm OK with most of that

I've managed to get a 83 track dump of the 1650A master disk (using the HNCfloppyemulator software) and I'm (pretty) confident that what I have is 'real' (it's attached). I did this on an old Portege 320CT running W2K. I tried other things too - OmniFlop and SAMdisk.

As I think this format is some-kind of bastardised variant of .LIF, I've compared the first bit of this dump to a successful read using OmniFlop's HP-1000 format (77/2/5x1024) and they 100% match, so I've no reason to doubt the extra 6 sectors will be fine. Let's assume the data is 'good' off the PC drive.

I've tried a huge number of variations of sector size/number of/sector ID start (when converting this raw data to a .HFE), non of which work. Looking at the data from the 4145B thread (which is based on the same drive), it would seem logical that the sectors are 256 byte. I also found some web mentions for the HP-9121 which seem to imply that drive had 83/2/16x256, so that ties up, but who knows. I know the bit rate needs to be 500,000.

I'm not sure where to go from here as I feel I'm stumbling around as bit. I've got the hardware fitted nicely (pics when it works!), but that's kinda where I am as of now.

I'd quite like to know what 'format value' on the Load RAW image tab of the HNCfloppyemulator means, but I'm assuming leaving that at 246 makes zero difference?

John

[Jeff]

If you have used the hxc tool to dump your disk, with have you not saved it into the hfe format directly ?
This format store any details about the disk format.
Please share the hfe file.

[jwpgroup]

Hi Jeff

Thank you so much for replying.

OK, I've emailed you directly a dump of the same data saved directly as a .hfe. This file is (sadly) too big to load here (even as a .zip).

The ONLY change I've made (using Hex editor Neo) is to set the bitrate to 500,000.

Just to be sure, I've checked this doesn't work if I try it in the card 'as is'.

Best

John

[jwpgroup]

Hi Jeff

just to let you know, I've still not been able to sort this.

I've now done quite a lot of investigation in collaboration with Simon Owen (SamDisk's author), but we've not got a solution as of yet

I'm assuming you got the floppy I sent you in the post and I wondered if you had any thoughts? In particular, could you shed any light on
what (if anything) the various disk modes offered by changing bit 0x10 of the .HFE might do to help?

FYI, I have been able to make a LIF disk on a PC using these instructions...

http://sci.tech-archive.net/Archive/sci ... /0635.html

Which boots fine.

Converting that file (like the original disk I sent you), still gets us nowhere.

I'm pretty convinced I've got the hardware connection right, as I've done what the guys in the 4145B thread did (which uses the same drive).

As a last try, Simon is going to try to convert from his .scp (SuperCard Pro flux image) to .hfe at flux level to avoid any image differences.
It seems that the current conversion program performs a high-level sector extraction, and then converts that to HFE, which is similar to starting
from a sector-based image (such as hp1650a.dsk). Simon noticed that HxC disks include an IAM (index address mark), which the original disks
don't have. We are clutching at straws tho.

FYI, the FDC is a Standard Microsystems FDC9793.

Any input you have would be very useful.

Best

John

[Jeff]

As a last try, Simon is going to try to convert from his .scp (SuperCard Pro flux image) to .hfe at flux level to avoid any image differences.
It seems that the current conversion program performs a high-level sector extraction, and then converts that to HFE, which is similar to starting
from a sector-based image (such as hp1650a.dsk).

Which is completely wrong. With the HxC software, the SCP->HFE conversion doesn't extract any sector. this is a direct stream to cells conversion.
Please send me this SCP file.

I'm pretty convinced I've got the hardware connection right, as I've done what the guys in the 4145B thread did (which uses the same drive).

i am not . And this is probably the issue.
At which speed is rotating the original disk drive ?

[jwpgroup]

It's 600rpm. I sent you (a while back) the data sheet (but I'm sure you get inundated).

I've got the data sheet for the FDC too if it helps.

I haven't got the SCP file, but I'll ask Simon for it when we next touch base.

I'm 'tweaking' the data rate to be 500,000 (so 01F4) from the 250,000 original (00FA), but it makes no difference.

Here's the hardware Mod...

JWPhxcMod.jpg (140.35 KiB) Viewed 12234 times

Best

John

[jwpgroup]

As a last try, Simon is going to try to convert from his .scp (SuperCard Pro flux image) to .hfe at flux level to avoid any image differences.
It seems that the current conversion program performs a high-level sector extraction, and then converts that to HFE, which is similar to starting
from a sector-based image (such as hp1650a.dsk).

Which is completely wrong. With the HxC software, the SCP->HFE conversion doesn't extract any sector. this is a direct stream to cells conversion.
Please send me this SCP file.

How do you account for the IAM (index address mark), which the original disks don't have? - Is that being 'added' during the conversion?

I'm out of my depth here, so go easy

Best

John

[Jeff]

How do you account for the IAM (index address mark), which the original disks don't have? - Is that being 'added' during the conversion?

I don't know at all what Simon have done.
I don't have any IAM with my conversion here.

Here is my dump results :
https://hxc2001.com/download/floppy_driv ... A_BOOT.zip
Just copy the HFE & CFG file to the SD.

[jwpgroup]

I'm not really sure myself, I'll point him here so he can join in

Those files don't work sadly.

I changed the tracks from 85 to 83 (after my 1st test) but that also made no difference.

Gotta be missing something, just don't know what.

Thanks for trying.

Best

John

[Jeff]

Hardware issue probably. Are sure that the drive is rotating at 600RPM ? Can you check this point ?

Also try to set the switches ID0-A+ID1-A+ID2-A+ID3-A to ON.

[jwpgroup]

All the switches on (0-3) makes no difference.

The drive spec is 600RPM and a bit rate of 500K.

How is the drive speed set (or is it just ultimately the data throughput? - so 01F4 vs 00FA)

I tried all on and 250K/500K, just 0 on 250K/500K. All no go.

Best

John

[Jeff]

If you are 100% sure that the drive rotate at 600RPM. Don't touch anything on my image and cfg file, it is set correctly.
have you the last firmware ?

https://hxc2001.com/download/floppy_driv ... rmware.zip

[jwpgroup]

Here is the signal and timing specs...

MP52Wsignals.zip

(208.03 KiB) Downloaded 698 times

MP52Wspec.zip

(167.46 KiB) Downloaded 638 times

[jwpgroup]

If you are 100% sure that the drive rotate at 600RPM. Don't touch anything on my image and cfg file, it is set correctly.
have you the last firmware ?

https://hxc2001.com/download/floppy_driv ... rmware.zip

I ordered the board end Jan, it arrived mid Feb.

Best

John