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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 1st Jun 2021, 3:47 pm   #1
Mark1960
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Default Dataman Microdoctor

While searching for SCMP related material I saw this advert in Wireless World, August 1982, page 23 by Dataman Designs. As it seems it might be related to Softy 2, I was wondering if anyone had any memories of this device.

https://www.***********/document/500...-1982-08-S-OCR

The link was from scribd, but doesn’t seem to be accepted by the forum.

Last edited by Mark1960; 1st Jun 2021 at 3:50 pm. Reason: Try to fix link
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Old 1st Jun 2021, 4:35 pm   #2
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Default Re: Dataman Microdoctor

Maybe here?
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Old 1st Jun 2021, 5:02 pm   #3
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Default Re: Dataman Microdoctor

Thanks to bluepilot for the working link.

That microdoctor is similar in concept to the idea of using an Arduino to replace the CPU in a system so it can read from / write to areas of the RAM and various I/O devices to check things out, only it is purpose made for that use.

Those are likely to be even rarer than the Softy 1 and Softy 2.
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Old 2nd Jun 2021, 6:04 am   #4
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Default Re: Dataman Microdoctor

I do actually have a Dataman Microdoctor, after spotting it at a radio rally for a few pounds many years ago, having never seen one before - or since. And more recently, I have seen the Dataman adverts which featured these.

They were an interesting product, that you plugged into a target system, via the processor socket (with the IC completely removed) and there was a collection of 'personality' module PCB's that plug into the main unit to map the pinout for the desired 8bit processor. So it supported several popular Z80, 6502 & 68xx types.
I recall it would search the memory-map for RAM etc. and would let you test that. Plus it probably did ROM Checksums etc. All output from it was via its built-in till-roll printer.

I don't recall ever finding much on the 'net about it, so will have to dig mine out and take some internal photos / try and readout any firmware etc. And maybe scan the manual, I think I got with it.
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Old 2nd Jun 2021, 6:52 am   #5
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Default Re: Dataman Microdoctor

How odd, to use a printer as output to the user when the S1 / S2 had video output. Anything which only output to hard copy would tend to discourage you from using it - should you use / waste more of your previous paper, or not?

Surprising you've only mentioned this now, Owen, makes me wonder what a multitude of other things you must have which you also haven't mentioned yet.
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Old 2nd Jun 2021, 7:49 am   #6
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Default Re: Dataman Microdoctor

Yes, a serial output / scrollable small LCD would be far more useful these days! And their Menta Z80 unit was display-based.
So it's a bit like a vintage mainframe system, having everything literally-printed - something you'd see in 60's films / on Avengers episodes etc,
Maybe the idea was that you attached the printout to the computer as a repair ticket or proof of fault / being fixed - Although custom diagnostic software would probably be better. I do recall some computer hardware (and often still test equipment) coming with manufacturer production-test printed results.

It did actually still print when I last tried it, but suspect the ink cartridge / pen would have dried-out by now and not sure if these would still be available. I do have a few till-rolls of various-sizes and believe these are still available (even if most are now using thermal paper).

I had actually mentioned iit on here before, during Dataman Softy etc. discussions and I've had a brief rummage through one computer-stuff storage room, but I haven't spotted it (I'm sure I got it back after lending it)
- Although I did find many obscure Z80 etc. PCB''s I need to find-out what they are, I'd forgotten about. So need a bit more searching / thinking where I last put it!

I would certainly have taken it apart when I got it, to see what's inside. But it was probably before I had a digital camera, so not yet got any photos. But I suspect there's a Z80 (seems Dataman moved onto that after SC/MP) etc. and an EPROM + some RAM in it.
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Old 2nd Jun 2021, 10:06 am   #7
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Default Re: Dataman Microdoctor

What sort of printer mechanism is it? If you're lucky it'll be one of the Epson M150 or M160 ones. Those are still being made, and ribbons are not hard to get (even RS stock them)
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Old 2nd Jun 2021, 11:02 pm   #8
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Default Re: Dataman Microdoctor

I'm not sure what the exact mech. is, until I find mine + look inside. But I recall it was a fairly narrow (approx. 2" wide) one - similar size to Anritsu MD6420 Data Transmission Analyzers built-in printer, compared with wider (approx 4"?) type built into some old large Gould DSO's. However, the Microdoctor case is quite low-height, so probably has much-smaller mech. as till-roll is external - as no room to hold it in unit.

But, from quick search for Dataman Microdoctor Printer Paper, I've found a Dataman advert sold 10 rolls of Thermal paper for 9.
https://worldradiohistory.com/hd2/ID...-Page-0081.pdf - Wasn't a bad price, but I hadn't thought output looked like thermal paper.
(I'm sure my keypad was more of a membrane, so maybe there was more than one version of it).

I also see it had a built-in disassembler for the various processors, that I'd forgot about - just to use up your paper rather faster!
I'm sure I had a range of 'conversion card' adaptors with it, but don't recall having alternative ROM's that's supplied with each of these.

These are the details copied from the OCR'd magazine-page advert:

BUS EXERCISER/DIAGNOSTIC AID

RAM and I/0.
Prints memory contents in HEX, ASCII or ASSEMBLER MNEMONICS.
Prints MEMORY MAP of addressing space. Performs CHECKSUMS. TESTS RAM, prints addresses and bits which default.
Tests data lines for SHORTS to rails, other data or address lines. Tells engineer of address/data faults impossible to find with other tools
Easy to program: retains sequences for testing up to fifteen different
products in permanent memory.

Microdoctor is supplied in Z80, 6500, 6800 and 8085 format with appropriate disassembler (say which you want). MICRODOCTOR 295.00
Conversion card & ROM (Changes configuration and disassembler e.g. Z80 to 6500 say which) 35.00
Clip-over PROBE only needed if uP is soldered -in) 35.00
10 Rolls Thermal Paper 9.00

Last edited by ortek_service; 2nd Jun 2021 at 11:15 pm.
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Old 2nd Jun 2021, 11:17 pm   #9
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Default Re: Dataman Microdoctor

I think if I had one and wanted to play with it I might be tempted to unplug the printer from the PCB and hang something on the printer connector - a 5V-friendly Arduino probably - and have that reconstruct whatever the PCB outputs to the printer back into text to be transmitted serially. That way I wouldn't feel constrained by the available supply of vintage printer paper.

It's a bit disappointing that it only seems to support a choice of one microprocessor out of the box, at least in terms of the disassembler. I wonder if that is determined by the specific version of firmware fitted, in which case your example may be dedicated to whichever micro its fitted firmware happens to support.
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Old 3rd Jun 2021, 7:56 am   #10
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Default Re: Dataman Microdoctor

If the printer interface is just sending ASCII to it, then conversion to a serial terminal display shouldn't need much - maybe able to do it with just a logic IC or so, without needing any uC / firmware.

Yes, it does seem that you need a different (EP)ROM installed for each Z80, 6502, 6800 or 8085 plug-in 'conversion card' PCB adaptor module, rather than just having one program that detecting what adaptor you had.
I suppose this made it simpler to add extra processors they added in future, as you still might have to update a larger EPROM to latest version
- at least with later Softy S3, you uploaded a 'Help ROM' into battery-backed RAM to ensure that its library of devices was fully up to date, for support of the later devices.

I did also notice they sold a clip-over Probe, in case the CPU was soldered-in. - Presumably you needed a different one for each CPU, and it wasn't universal (although not clear from the advert)

I think an updated more-modern maybe Arduino (Mega?) / RPi based version of the Microdoctor could be very useful to aid fixing vintage computers, but I've not really seen anything quite like this. Many years ago, a friend was working on something similar, using an FPGA etc. for Atari Arcade machines, but I think these already had a diagnostic connector and Atari had originally produced a (similarly to Microdoctor, quite rare) unit that plugged into this (May have been a JAMMER? interface, used on other makes).
But once the hardware / firmware of the Microdoctor gets Rev-Eng'd, then that might be helpful in basing any future design on what it did without having to start from scratch too much.
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Old 3rd Jun 2021, 9:21 am   #11
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Default Re: Dataman Microdoctor

We looked at the idea of doing something like this with an Arduino Mega in ScottishColin's PET repair but the situation there was complicated by the fact that the system had dynamic RAM and all the timing for that was derived from the 'clock 2' output on the 6502, so the Arduino impostor would have had to try to generate all needed signals with the correct relative timing, even if it drove the whole thing in slo-mo - but not too slow, because otherwise it might have failed to refresh the RAM in time.

That, and the lack of a similar system for me to try it in myself first, was the main reason we didn't attempt it and in the end made the necessary diagnois by running test code kindly provided by Slothie and Daver2 on the machine itself, something it was fortunately able to do.

Trying to do it with an Arduino would have generated more questions than answers, most likely. You'd have to get a system like that working on a definitely known working host system and producing sensible results from that first before then trying to use it on a broken system.
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Old 3rd Jun 2021, 9:45 am   #12
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Default Re: Dataman Microdoctor

I believe the Microdoctor was particularly aimed at use with ZX Spectrums etc - All DRAM. So I presume it must have coped with that.
I guess that if your're cycling through all the RAM / memory-map, to test it, then that should automatically refresh it. And you're not too worried about the RAM keeping any contents from what it would hold when computer is running normally.
Screen RAM may be a bit more troublesome, if processor is not able to read back from it. Or there's some paging being done like on C64 and later Acorn ones with 'Sideways' RAM (But you could create a customised test for those - at least on something you had full h/w details / firmware source for)

Yes, trying to develop something to fix another thing that's broken means you've then got 2 unknowns. So do really need some working computers to develop a diagnostic aid on (but some broken ones can also be useful, to ensure it finds the faults). However, as it's based around particular processors and their buses, you may not necessarily need a PET but could use another 6502 computer. But any oddities like RAM that doesn't directly read back / paged RAM can cause issues. And particularly with the PET, Memory faults may be actually down to its multitude of Buffers.
However, have an known-working debug system like the Microdoctor could still be useful as an initial check for stuck bus lines and checksumming ROM's in circuit - particularly without needing a working processor installed.
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Old 3rd Jun 2021, 10:04 am   #13
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Default Re: Dataman Microdoctor

I've just looked at an older (Mar'83) advert, from (OCR'd) scanned magazine page here:
https://worldradiohistory.com/hd2/ID...-Page-0025.pdf (than the Mar'84 advert I'd previously looked at).

Which has a bit more / different details, saying:

Microdoctor is an alternative to AUTOMATIC TEST EQUIPMENT which can be very expensive. MICRODOCTOR is perfectly adequate for diagnosing faults in microprocessor boards or computers in the REPAIR SHOP or on the PRODUCTION LINE.
Reports are PRINTED on the integral thermal printer. Tests supported are CHECKSUM, RAMTEST, WAIT, READ, WRITE, I/O READ, I/0 WRITE, DUMP IN HEX, DUMP IN ASCII, TEST DATA LINES (for shorts between data, address and rails), SEARCH (for two specified bytes), MAP (print a memory map of ROM, RAM, I/O and EMPTY SPACE).

Supports both multiplexed and non -multiplexed address/data. Standard software will also DISASSEMBLE in Z80 mnemonics - other disassemblers cost extra. Programs for board -testing can be written in MINUTES - and retained for MONTHS even if the power is switched off (CMOS RAM is backed -up with rechargeable battery). Capacity is 15 different programs of 12 tests each.

Included are two PROBE CONFIGURATION CARDS (One Z80, other uncommitted), PROBE with 24 inch cable and 40-pin DIL plug - and POWER SUPPLY. 295 (+VAT). Extras available are
6502 disassembler retrofit 35,
Clip-over PROBE (only needed if uP is soldered-in) 35.



So it seems you originally got a spare blank Configuration card board, that you could wire-up for use with other (6502 / 6800 / 8085 etc) processor sockets.
And that you could write various test 'programs' for it, that it held in battery-backed RAM. Although I'm not sure how complex these programs could be, or whether they were just a sequence of standard tests it did.

Last edited by ortek_service; 3rd Jun 2021 at 10:10 am.
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