VOGONS


First post, by matze79

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Hi,

this is a thread about Patching Tandy Games to 0E0 Port.

with debug.exe (MS-DOS Command) this can be done really easy, gamma from dosreloaded.de showed me howto make small adjustments to com files.

i patched digipak driver for tandy ex/tx, now its working with Port 0E0h.

Disassemble your Program (nbasm is really good, choose 16bit Mode)

We are looking for OUT C0,AL, lets see what it is in HEX Format

Use MS-DOS Debug:
debug
-a
out c0,al
(enter)
- u

We get this:
xxxx:0100 E6C0 OUT C0,AL

Now lets search for the opcode in hexformat:

debug myfile.com
-s 0 ffff e6 C0

Now we get several Hits:
--> 1. 1 Hit at xxxx:05AC

We examine the Position:
-u 05AC

We get: "xxxx:05AC E6C0 OUT C0,AL"

Now lets change the position to "out e0,al":
-a 05ac
OUT e0,al
(enter)

lets check if everything is right:
-u 05ac

--> it changed
Lets repeat with all other Positions!

Save with:
-w
Quit with:
-q

This will work with files up to 64kbyte, note that debug will complain about i can`t save to EXE or HEX Format.. simply rename files should to the trick ( i did only try yet with Digipak Driver TANEXTX.COM which worked very well!)

Dissembler:
http://www.fysnet.net/newbasic.htm - NewBasic x86 Assembler
Requires cwsdpmi.
Grab it here: https://sandmann.dotster.com/cwsdpmi/

Thanks

Matthias

Last edited by matze79 on 2020-02-20, 12:03. Edited 1 time in total.

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 1 of 12, by matze79

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Sierra Demopac #1: (AGI2915)

Filename
demopac1_0E0.zip
File size
194.2 KiB
Downloads
50 downloads
File comment
Sierra Demopac #1
File license
Fair use/fair dealing exception

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 2 of 12, by matze79

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I think it would be possible to make some kind of autopatcher, like it exists for other Devices OPL2LPT for example.

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 3 of 12, by matze79

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F-19 Stealth Fighter

Filename
TSOUND.EXE.gz
File size
3.92 KiB
Downloads
43 downloads
File comment
Place in Game Directory
File license
Fair use/fair dealing exception

Zorro (Digipak Driver)

Filename
TANEXTX.COM.gz
File size
1.89 KiB
Downloads
42 downloads
File comment
Place in Game Directory
File license
Fair use/fair dealing exception

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 4 of 12, by keropi

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nice to see info on that!
patch some popular games - something sierra for example 😁

🎵 🎧 PCMIDI MPU , OrpheusII , Action Rewind , Megacard and 🎶GoldLib soundcard website

Reply 5 of 12, by matze79

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Already done, patched Sierra Demopac 1, you can upgrade most AGI Games to 2915 and use the Executable from the Demopac above 😀
Space Quest 1, Kings Quest 2 and Leisure Suit Larry etc should work just fine on 0E0.

Tried to patch Stunts, but somewhere there is still a instruction hidden, it simply does not play all channels.

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 6 of 12, by BloodyCactus

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the problem with doing 's' searches, you dont know if your in the middle of another opcode or not so dont be surprised if sometimes you do this change and you get reboots.

also does not take into accout doing it via dx as in out dx,al

but a good start anyways

--/\-[ Stu : Bloody Cactus :: [ https://bloodycactus.com :: http://kråketær.com ]-/\--

Reply 7 of 12, by matze79

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Police Quest 2

Filename
JR.DRV.gz
File size
1.36 KiB
Downloads
42 downloads
File comment
Replace JR.DRV
File license
Fair use/fair dealing exception

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 8 of 12, by matze79

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Silpheed
Codename: Iceman

Filename
JR.DRV.gz
File size
2.04 KiB
Downloads
40 downloads
File comment
Replace JR.DRV
File license
CC-BY-4.0
Last edited by matze79 on 2020-02-22, 20:58. Edited 1 time in total.

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 10 of 12, by matze79

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Already patched the AGIT2917, but still have not patched all.

i trying some more funny Stuff, like disassembling and reassembling..
i got some small Games for testing.

https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board

Reply 12 of 12, by carlostex

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Any point in continuing to pursue port 0E0h? Port 090h seems a much better candidate to work in systems from 286 up to Pentium when port 0C0h does not work. At least on my Intel 430TX system port 090h worked well vs port 0E0h or others i tried. Only systems that port 090h won't work is on IBM PS/2's, but those can probably use 0C0h and are MCA anyway. Once we have a good 8bit port for all systems then i could repatch all the games i have patched for the repo, and keep them organized and properly separated.

psychofox wrote on 2020-10-22, 19:43:

Thank you, could it be possible to patch Microprose Airborne Ranger please?

Airborne Ranger is one lucky case where there's no absolute need to patch. Rename the IBMSNDS.EXE to something like BEEPER.EXE and make a duplicate of TANDYSND.EXE and rename the duplicate to IBMSNDS.EXE. If you need the routines on 0E0h just patch the renamed file instances of E6 C0 to E6 E0. Use a Hex Editor.