Identifying Atari 400 upgrades

[Almost Rice]

I posted some pics yesterday on this machine I just got.

 

There is a board with Omnimon attached at C199 socket. There is a name on the a chip on the Omnimon board. Is it significant? Also the ram card has been replaced with the MM6448 card from INTEC Peripherals. It may be 64K since the front shows only 8 ram chips, but the OS still looks like 400/800 not xl/xe.

 

I don't know what the switch if for.

 

I will try to get better pics, but I don't feel like opening it at this time.

Edited November 22, 2005 by Almost Rice

[deathtrappomegranate]

The Intec MM6448 is a 16K RAM board.

 

I'm afraid that the other pics are a little too blurred to make out.

Edited November 19, 2005 by deathtrappomegranate

[classics]

I imagine the switch is for switching between the standard 400/800 OS and the Omnimon OS.

 

Put the switch in one position turn on the computer. Then when its at the memo pad or basic screen, hold down SELECT and tap RESET.

 

If the Omnimon is enabled it will come back in the machine language monitor, if not it will just return to basic or memo pad.

 

Try it again with the switch in the other position. If its the OS switch then you should only be able to enter omnimon with it in one of the positions.

 

Steve

[Rybags]

Most >48K memory upgrades on the 400/800 map 4K banks at $C000-$CFFF.

 

Try POKEing and then PEEKING 49152 to see if there's RAM present.

[Almost Rice]

Put the switch in one position turn on the computer.  Then when its at the memo pad or basic screen, hold down SELECT and tap RESET.

 

If the Omnimon is enabled it will come back in the machine language monitor, if not it will just return to basic or memo pad. 

Steve

968579[/snapback]

 

Hi Steve,

 

The Screen comes back with:

Davic Young OMNIMONA3 ©1984

  PC NV-BDIZC AC X  Y  SP

GF6E4    21    0C 80 01 1DF

 

 

 

So, is this for programming?

[Almost Rice]

Most >48K memory upgrades on the 400/800 map 4K banks at $C000-$CFFF.

 

Try POKEing and then PEEKING 49152 to see if there's RAM present.

968621[/snapback]

 

When I PEEK (106) I get 160.

 

So,

160*256=40960 bytes

 

I get the same on my 130XE. Basic Rev. C and Basic XE. I have forgotten what I needed to do to access the extra space with BXE.

 

This page documents the PEEK

[Rybags]

The OS only checks for contiguous RAM when booting. So, the only way to have it see 52K of RAM would be to have no cartridge inserted.

 

I don't know if BASICXE will recognise that type of RAM upgrade (if it's actually installed).

[Almost Rice]

I don't know if BASICXE will recognise that type of RAM upgrade (if it's actually installed).

968781[/snapback]

 

I was referring to the 130xe. I could not get the BXE cart to work with the 400. It did not expect it to work anyway.

[classics]

Hi Steve,

 

The Screen comes back with:

Davic Young OMNIMONA3 ©1984

  PC NV-BDIZC AC X  Y  SP

GF6E4    21    0C 80 01 1DF

 

 

 

So, is this for programming?

968624[/snapback]

 

Yes, its a rom debugger. The F6E4 listed is the address the program was running at when you pressed reset.

 

You can get the documentation for the Omnimon here:

 

http://www.strotmann.de/twiki/pub/Infothek...Mon/OmniMon.pdf

 

Steve