RamboXL upgrade and the 800XLF........slight problem...

[Beeblebrox]

So I purchased a RamboXL board (Mytek's excellent design). Installed this with no issues in a stock 800XL of late.

 

 

Just been socketing the ram on my 800XLF (the one with the freddie), for this install.

 

No sooner had I finished I realised the 800XLF doesn't have the 74LS158 chips on board. The Rambo board normally plugs into where the upper 158 chip is located which I normally socket and plug the RamboXL PCB into as illustrated in the stock 800XL above.

 

So bottom line - does this mean I can't install the RamboXL 256k board in an XLF and thus do the upgrade? Or is there a clever workaround? For example can I do the RamboXL upgrade another way, perhaps even without using the RamboXL PCB here? 

 

A stock 800XL:

 

 

The XLF (No 74LS158 on the board at all, probably because Freddie chip incorporates the Logic):

 

 

Edited March 26, 2023 by Beeblebrox

[TZJB]

1 minute ago, Beeblebrox said:

So I purchased a RamboXL board (Mytek's excellent design). Installed this with no issues in a stock 800XL of late.

 

 

Just been socketing the ram on my 800XLF (the one with the freddie), for this install.

 

No sooner had I finished I realised the 800XLF doesn't have the 74LS158 chips on board. The Rambo board normally plugs into the upper 158 chip which  normally socket as illustrated in the stock 800XL above.

 

So bottom line - does this mean I can't install the RamboXL 256k board in an XLF and thus do the upgrade? Or is there a clever workaround?

 

A stock 800XL:

 

 

The XLF (No 74LS158 on the board at all, probably because Freddie chip incorporates the Logic):

 

 

 

RamboXL was not designed for a 800XLF as it is basically a 65XE without the niceties so no workaround to my knowledge. Atari 130XE type solutions are a possibility using a 256K SIMM maybe but it's a big pain. More recent 512KB SRAM or U1MB solutions are more elegant. PBI plug-in memory expansions like an AVG cart will obviously work too.

 

 

[Beeblebrox]

17 minutes ago, TZJB said:

 

RamboXL was not designed for a 800XLF as it is basically a 65XE without the niceties so no workaround to my knowledge. Atari 130XE type solutions are a possibility using a 256K SIMM maybe but it's a big pain. More recent 512KB SRAM or U1MB solutions are more elegant. PBI plug-in memory expansions like an AVG cart will obviously work too.

 

 

 ok TZJB - least I know now.

[Beeblebrox]

Incidentally I did find this which is an XLF compatible 512k upgrade:

 

https://abbuc.de/forum/viewtopic.php?t=153

 

Edited March 26, 2023 by Beeblebrox

[TZJB]

26 minutes ago, Beeblebrox said:

Incidentally I did find this which is an XLF compatible 512k upgrade:

 

https://abbuc.de/forum/viewtopic.php?t=153

 

 

That is the HIAS 512KB SRAM design and will need a programmed GAL22V10. It has an optional real time clock too.

 

Below is the TFHH 512KB SRAM version which I fitted to a standard 800XL but it fits in all Atari XL/XE including the Rose 800XL (XLF) with the exception of the 600XL.

 

 

It's quite neat and sits in the Antic socket requiring only the 4 extra wires to be connected. The screening doesn't fit afterwards however.

 

Edited March 26, 2023 by TZJB