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Model III BASIC ROM image/binary files
- Thread starter GK2001
- Start date
ldkraemer
Veteran Member
Yes, they are on the internet. If I remember right they are in David Keil's Emulator package too. Are you looking for the
three separate files or one combined file.
The model 3 contains 14K of ROM (in Model III Mode) divided into:
U104 ROMA MCM68A364 8K Manuf Part Number 8041364 0000-1FFF = 8192
U105 ROMB MCM68A332 4K Manuf Part Number 8040332 2000-2FFF = 4096
U106 ROMC MCM68A316 2K Manuf Part Number 8040316B 3000-37FF = 2048 less 37E8-37E9 = 0xFF
https://edgeemu.net/browse-mame-T.htm
I sent you a PM.
Larry
three separate files or one combined file.
The model 3 contains 14K of ROM (in Model III Mode) divided into:
U104 ROMA MCM68A364 8K Manuf Part Number 8041364 0000-1FFF = 8192
U105 ROMB MCM68A332 4K Manuf Part Number 8040332 2000-2FFF = 4096
U106 ROMC MCM68A316 2K Manuf Part Number 8040316B 3000-37FF = 2048 less 37E8-37E9 = 0xFF
https://edgeemu.net/browse-mame-T.htm
I sent you a PM.
Larry
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Eudimorphodon
Veteran Member
Looking through MAME collections usually works for this sort of thing. A while back I had the need for a copy of the Model III’s character generator ROM and the MAME set had that, which was great. (I was getting to the point I thought I might have to make a synthetic one by using the data embedded in the SDLtrs source code.)
Oh wow, thanks for that link. That's a great resource there!
I downloaded the TRS-80_Model_III.zip and that appears to contain all I need. I take it Model III BASIC went through a few revisions as there are three versions of U106 and two versions of U104.
U106:
276a
8040316b
8040316c
B and C only differ from each other by a few bytes, but they are a major revision over A.
U104:
8040032
8041364
This one has me puzzled as the earlier version is only 4KB rather than 8KB.
Did the very first Model IIIs only have 10KB of ROM?
EDIT: never mind, found the answer to U104:
"Model III ......... you can start with a 4K Level I system and let it grow with your needs....... Available with either Level I or powerful Model III BASIC."
http://www.trs-80.com/wordpress/trs-...ine/model-iii/
Still would like to know the revisions made with U106.
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gp2000
Experienced Member
I think the may difference between the first Model III, Level II (i.e., 14K) ROM and latter ones was keyboard input. In the later versions SHIFT + down-arrow worked as a control key. Used in combination with A-Z and perhaps some others it could generate control codes (0 - 31 range). And there was a SHIFT + down-arrow + key combination which would dump the screen to the printer.
The first ROM had none of the SHIFT + down-arrow key stuff. However, they did throw in a feature where if both 'P' and 'S' keys were held at the same time the screen would be printed.
Learned this the hard ware back in the day as my last name ends in "ps". Typing my name quickly would lock-up the computer as it tried to print when there was no printer attached. Fortunately my brother and I figured this out fairly quickly after some considerable concern that our brand-new Model III was broken. Just hold down on the BREAK key to wake it up. If you were typing in a line of BASIC code you got to start over.
We also couldn't figure out why we were unable to trigger any of the fancy key combinations listed in the manual.
The first ROM had none of the SHIFT + down-arrow key stuff. However, they did throw in a feature where if both 'P' and 'S' keys were held at the same time the screen would be printed.
Learned this the hard ware back in the day as my last name ends in "ps". Typing my name quickly would lock-up the computer as it tried to print when there was no printer attached. Fortunately my brother and I figured this out fairly quickly after some considerable concern that our brand-new Model III was broken. Just hold down on the BREAK key to wake it up. If you were typing in a line of BASIC code you got to start over.
We also couldn't figure out why we were unable to trigger any of the fancy key combinations listed in the manual.
Yep.
"v1 – First released version. U.S. Version (60Hz). Did not allow control codes to be entered from the keyboard although those codes were documented in the owners manual."
http://www.trs-80.com/wordpress/zaps-patches-pokes-tips/rom-checksums-for-model-3/
"v1 – First released version. U.S. Version (60Hz). Did not allow control codes to be entered from the keyboard although those codes were documented in the owners manual."
http://www.trs-80.com/wordpress/zaps-patches-pokes-tips/rom-checksums-for-model-3/
Old thread bump....
I've managed to verify that Level I, 4096-byte ROM A (U104) binary file that I found (8040032) by running it in the TRS32 emulator in Model III, level I mode:
This Model III Level I ROM image is a significantly modified version of the original Model I Level I ROM.
Given that an entry-level Model III could be bought back in the day with Level I BASIC, I presume that it might have been packaged with a version of a Model III operational Manual detailing Level I BASIC. However every Model III manual I can find on-line is devoted exclusively to Level II BASIC. The service manuals too only give Level II part numbers for the ROM ICs.
Does anyone know if a Model III, Level I manual ever existed? I'd like to know what the differences might be between the Model I and Model III Level I ROMs.
https://www.trs-80.com/wordpress/zaps-patches-pokes-tips/rom-checksums-for-model-3/
Also, can anyone suggest why Ira Goldklang's webpage above suggests checksum values for ROM B and ROM C for a Level 1 machine? I would have assumed that the sockets for ROM B and ROM C in a 4KB-ROM Level 1 Model III would have been left unpopulated. Incidentally, the 16-bit Level 1 checksum for ROM A given there (BBC4) does not match the 8040032 Level I ROM image that I have. I get F9A8.
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Trash-Eighty
Experienced Member
This morning I've found two photos in my archive.
One showing a Model III Level 1 BASIC motherboard. Yes, there is only one ROM chip for the Level 1 machine.
The other photo shows a Level 1 manual for the Model III.
Both photos are from unknown internet sources and I don't have any further information about them but I hope it helps a bit.
-Rainer
One showing a Model III Level 1 BASIC motherboard. Yes, there is only one ROM chip for the Level 1 machine.
The other photo shows a Level 1 manual for the Model III.
Both photos are from unknown internet sources and I don't have any further information about them but I hope it helps a bit.
-Rainer
Attachments
Trash-Eighty
Experienced Member
And meanwhile I have doug even further in my archive and found a pdf file of the Level 1 User's Manual for the Model III.
Here is a link to it: https://drive.google.com/file/d/155c6gvRElY5WP1FlhQP6wCWjx3mSlhvm/view?usp=sharing
Here is a link to it: https://drive.google.com/file/d/155c6gvRElY5WP1FlhQP6wCWjx3mSlhvm/view?usp=sharing
Awesome, thanks! That is exactly what I was looking for. Nice high-res. photo there; the Radio Shack part number (8040032) on the half-filled 64K-bit ROM (U104) is easily readable. This matches the file name of the ROM image that is out there.
The manual is a version of the D A.Lien Model 1 user's manual, amended to suit the Model 3. The "Summary of Level 1 BASIC" at the end of the manual quickly confirms that the only addition to Level 1 BASIC for the Model 3 was LLIST and LPRINT.
Can confirm that the ROM image out there doesn't reject these additions with a WHAT? :
Comparing this Level 1 ROM with the Model 1 version, barely a byte compares and the code was heavily rearranged/restructured. Impressive that they managed to optimise the code enough free up enough bytes to squeze in LPRINT and LLIST and still keep it to the original 4096 bytes. That heroic effort on the face of it seems a little masochistic, given that the U104 ROM in the Model 3 was 8192 bytes!
The manual is a version of the D A.Lien Model 1 user's manual, amended to suit the Model 3. The "Summary of Level 1 BASIC" at the end of the manual quickly confirms that the only addition to Level 1 BASIC for the Model 3 was LLIST and LPRINT.
Can confirm that the ROM image out there doesn't reject these additions with a WHAT? :
Comparing this Level 1 ROM with the Model 1 version, barely a byte compares and the code was heavily rearranged/restructured. Impressive that they managed to optimise the code enough free up enough bytes to squeze in LPRINT and LLIST and still keep it to the original 4096 bytes. That heroic effort on the face of it seems a little masochistic, given that the U104 ROM in the Model 3 was 8192 bytes!
gp2000
Experienced Member
I'd say the changes are relatively modest if compared at the source code level considering that they also had to change various routines to accommodate the differences in Model III hardware. The binary itself is quite different but that's just an artefact of the re-assembly. For details see http://48k.ca/L1Basic.html
BTW, you can also check these things out with
BTW, you can also check these things out with
trs80gp -m1 -l1 and trs80gp -m3 -l1With the exception of the Line Printer, Level 1 BASIC for the Model 3 didn't make use of anything in the Model 3, hardware wise, that was notably different from the Model 1. There might have been a register address here or there to change for the port over, but not much else. Most of the work would have been in finding enough free bytes to fit in the code for the new Line Printer commands.