VOGONS


First post, by Vallenrod

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Hello all,
Recently my Tandy 1000 RL HD has greeted me with the following images:

Built-in Deskmate (from rom), hdd disconnected:

tandy1.jpg
Filename
tandy1.jpg
File size
940.75 KiB
Views
313 views
File license
Public domain

Booted into dos from hdd:

tandy2.jpg
Filename
tandy2.jpg
File size
1.01 MiB
Views
313 views
File license
Public domain

Troubleshooting I have done thus far:

  • Tried two different Seagate xtide hdds 20MB and 40MB.
  • Booted with and without additional memory chips inserted.
  • None of the ICs on the motherboard seem to be unusually hot.
  • Performed "setuprl.exe /f" to reset bios to factory settings.

Any suggestions what the issue might be?

Last edited by Vallenrod on 2021-08-01, 23:20. Edited 1 time in total.

Reply 1 of 5, by Caluser2000

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Looks very much like a vram issue.

There's a glitch in the matrix.
A founding member of the 286 appreciation society.
Apparently 32-bit is dead and nobody likes P4s.
Of course, as always, I'm open to correction...😉

Reply 2 of 5, by Vallenrod

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Caluser2000 wrote on 2021-08-01, 20:17:

Looks very much like a vram issue.

It does indeed. However unexpanded Tandy 1000 RL uses the built-in 512KB RAM for video and when upgraded with additional 256KB it uses the first extra 128KB RAM to expand DOS RAM to 640KB and the other 128KB for video. Unfortunately in both cases the issue exists. I tested this with two different sets of 2x 128KB chips. So it's most likely something else.

Reply 3 of 5, by Cloudschatze

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Vallenrod wrote on 2021-08-01, 23:32:
Caluser2000 wrote on 2021-08-01, 20:17:

Looks very much like a vram issue.

It does indeed. However unexpanded Tandy 1000 RL uses the built-in 512KB RAM for video and when upgraded with additional 256KB it uses the first extra 128KB RAM to expand DOS RAM to 640KB and the other 128KB for video. Unfortunately in both cases the issue exists. I tested this with two different sets of 2x 128KB chips. So it's most likely something else.

Not exactly. The video chip is physically connected to 128KB of memory from the get-go - ICs U7, U8, U9, and U10. In an unexpanded system, the unreserved portion of this memory gets mapped into the 640K address space for system use. If there is indeed a VRAM issue, it won't relate to the memory in the U19 and U23 expansion sockets at all, but will instead be with one or more of the RAM chips in the four aforementioned locations.

Do you have anything installed in the ISA slot?

Reply 4 of 5, by Vallenrod

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Cloudschatze wrote on 2021-08-02, 02:13:
Vallenrod wrote on 2021-08-01, 23:32:
Caluser2000 wrote on 2021-08-01, 20:17:

Looks very much like a vram issue.

It does indeed. However unexpanded Tandy 1000 RL uses the built-in 512KB RAM for video and when upgraded with additional 256KB it uses the first extra 128KB RAM to expand DOS RAM to 640KB and the other 128KB for video. Unfortunately in both cases the issue exists. I tested this with two different sets of 2x 128KB chips. So it's most likely something else.

Not exactly. The video chip is physically connected to 128KB of memory from the get-go - ICs U7, U8, U9, and U10. In an unexpanded system, the unreserved portion of this memory gets mapped into the 640K address space for system use. If there is indeed a VRAM issue, it won't relate to the memory in the U19 and U23 expansion sockets at all, but will instead be with one or more of the RAM chips in the four aforementioned locations.

Do you have anything installed in the ISA slot?

Thanks for clarifying Cloud!
Nothing in the isa slot at the moment.