Re: DAS9100 does anyone still remember it


Brian
 

Hi Dan , nice to hear from you . I hope you are well and avoiding this virus .
I was surprised at how easy it seemed using GPIB with the DAS , mush easier than with some early instruments .
The damaged tapes that I have all have the broken elastic bands , the tape itself is quite undamaged , no sign of flaking oxide . I had a bad case of that with some old audio tapes .
I am very interested in your 29 pages of section 7 as I only have the 11 pages in my operator manual , it might open further possibilities with mnemonic files , all of which I will be quite happy to share with those interested and naturally will welcome any helpful suggestions .

I am starting to write a VB6 program that will allow limited control and data sending and retrieval via GPIB but I am not a VB programming expert by any means . Byte oriented binary data handling seems a bit awkward in VB and might take a while before it is working .
My GPIB interface is a USB to GPIB design from the internet that looks like the Prologix device and shares a subset of the same command set , so it should work with that device although I cannot say for certain as I dont have access to one , I can supply a link to the source of the device that I am using if it is needed , it is based on a PIC18F2550 .

The first mnemonic files I am likely to produce will be either 6800 or 8080 . If you know anyone with hands on experience of the PMA100 and knows if there is anything subtle that needs to be done to make it work , I would be pleased to know what it is . As far as I can tell the PMA itself just seems to be buffering and organising the data from the probes as there is no firmware inside , just a couple of 'PALs' in the logic . The PM105 for the Z80 has firmware as does the PM101 GP module but I dont know how it gets involved in operation -- the manuals I have for the PM modules only refer to operation with the 7D20 scope plugin . I dont know how relevant that information will be .
I will not let the PM issue slow things down .
I do have option 6 in my DAS and I had decided to try an LCD monitor to see what the display was like and if it was useful to have a bigger display -- have to see what the difference is with added BLUE or without .
I will keep in touch with progress

best regardsBrian Skilton

On Saturday, 11 April 2020, 00:02:54 BST, Dan G <dgajanovic@...> wrote:

Hi Brian,

Glad to hear that you were able to make progress on data transfer via the GPIB bus.

It looks like Tektronix designed a very reliable tape drive for the DAS9100, which has now,
unfortunately, far outlived any reliable tape cartridges. Even if one were to somehow get
freshly minted elastic bands for these old tapes that match the performance and reliability
of the originals, there is still the issue of the magnetic coating having become fragile with age
and prone to flaking off from the tape carrier.

An additional benefit of the GPIB transfer mode is that you will be able to easily share your
disassembly mnemonic tables with others. In theory, you should be able to get close
to re-creating the mnemonic tape contents from first principles.

I just looked at section 7 (Define Mnemonics Menu) of the DAS 9100 Operator's Manual PDF,
and noticed that the contents are far shorter and more limited compared to what I have on
paper (29 pages instead of 11). The version I have specifically talks about microprocessor
disassembly, and how to build a nested table structure with multiple mnemonic tables.

I could not find this version of section 7 online, so I will scan my copy and upload it to
TekWiki in the next few days.

Regarding your earlier question about external color monitors, I assume you have the
Option 6 I/O board, which provides color video output. Mine is Option 2, which only has
monochrome video output, so I cannot test this myself. However, note that the DAS only
generates three distinct colors: red, green and yellow. While the internal special-purpose
CRT has separate guns for red, green and yellow phosphors, an external monitor can produce
yellow by mixing red and green, so only two color signals are needed.
I expect that it should be easy to connect the Option 6 color video output to the
TTL-level input of a Commodore 1084 monitor or similar, but, again, I cannot test this
personally.


dan

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