Dazzler Tank War game

[johnx993]

Just wondering if anyone got this running from the paper tape file on the deramp site.
Space War runs fine for me, but Tank War goes someplace else in memory.
On the off chance, did Cromemco use a special 2 stage loader like MITS? I've not come across a Cromemco ptp loader.
Or is the paper tape file straight binary after the string of nulls at the beginning?
('2-stage' meaning there is code at the start of the paper tape that installs and runs a more robust loader after the initial one.)
-J

 

[daver2]

The file just looks like an 8-bit binary image that is copied directly into memory (at some address)

I assume the leader 00 is ignored.

How do you currently load Space War? The PTP file looks to be the same structure...

The instructions for Space War states that it starts at location 0 in memory. The hex dump clearly indicates that the program starts with a C3 (JMP) at location 0, but this ignores any leader tape.

The sample loader clearly will not work with leader tape either.

Ah, I found this helpful statement in the Game of Life manual:



Dave

 

[johnx993]

Yes, did notice Spacewar jumps to within itself.
However Tankwar looks like it's setting the stack pointer.

I run Spacewar by taking the binary file (by removing the initial NULLs), and attaching a loader header.
This is necessary because the monitor I use uses low RAM. And I need the monitor to use XMODEM to load the binary file.
I use XMODEM to load the file to 1000h, then use the monitor to jump to 1000h.
When it runs, it copies itself to 0000h and starts executing.
Only downside is I need to restart the Altair to get back to the monitor when I'm finished playing the game.
And I've checked, both Spacewar and Tankwar are less than 4K, so loading to 1000h should not overwrite anything.
And this particular machine has 16K RAM, and it tests good.

Digging through my doc archive, I see the LIFE manual you reference. Both LIFE and Spacewar have these older style manuals.
The loader code in the LIFE manual looks to be a simple binary loader. So that's good.
However Tankwar seems to be a newer game; I can only find docs for it in a Cromemco Games manual that refers to diskettes and a Z-80 system.
It may be that the 8080 is trying to run some Z-80 specific code and that causes problems.

As a test, I attached the LZE loader code (Load-Zero-Execute) to the Cromemco CHASE and TRACK games. Both worked fine.
So... I'm starting to think, if the Tankwar binary isn't damaged somehow, then there must be some Z-80 code in there.
-J

 

[daver2]

Oh well... It was worth a try...

 Dave