XE specific PBI implementation info required

[candle]

XE come in few flavours:

 

65XE (C07025) - without ECI port, thus without PBI support, 1bit RAM chips

 

65XEN (C100455) - first version with ECI port, 1bit RAM chips

 

130XE (C070067) - this is similiar board to the XEN board, but has two rows of 1bit RAM chips

 

65/130XE (C103579-001) marked as 130XE(64x4) - 2 or 4 RAM chips + ext RAM MMU unit (or 3 jumpers for 65XE)

 

and 800XE, but i don't have this board - basically the same as the previous one

 

last two (65/130 and 800xe) are pretty common in Poland

 

As Hias suggested, i've shortened the write cycles for RAM (from 260 to 190nS) and modified equations in one of IDEa GAL chips so it would follow precisely SRAM read and write timings - now memory access is perfectly stable on all of my 4 XE systems with ECI port - i would like to test it on XL series, but i don't have proper connector to plut the board in

 

orginally interface would work only in 65XEN computer - this one was without any modifications

now it works with them all - including even heavly modified one without any retuning

 

edit: just tested with the 5th system, and it also works without any futher modifications

Edited September 10, 2009 by candle

[Rybags]

AFAIK, all 600/800XLs and all of the XEs have the PBI code in their factory OS.

 

The XE even still has the F-key handling built in, which is a hangover from the 1200XL.

 

IIRC there are 3 main variants of the XL/XE OS that came after the 1200XL.

 

The one found mainly in 600XL will do an immediate Coldstart call if a cart is inserted or removed.

The one found in other machines will call a disabled loop if a cart is inserted/removed, the user must press RESET, which then Coldstarts.

 

The one for the XEGS has the altered startup to cater for keyboard, holding SELECT to override the default running of BASIC or Missile Command.

 

Then you have the version that can Self-Test expanded RAM for 130XE, but from what I've read around here, it's not so common.

[MEtalGuy66]

@Candle: Wow.. Thats amazing.. I guess it could have been for some version of the 65xe (some lacked the ECI port) or maybe the XEGS, even though all the production ROMs Ive seen for both those machines appear to be standard XL/XE OS ROM images of one version or another.. Thats strange..

 

@Rybags: yep.. And interestingly enough, the XEGS has the code to detect & test the extended RAM in it's self-test even though non of them were built with extended ram! I think they just stuck a late 130XE OS image in the 32k ROM along with basic & missle command..

Edited September 10, 2009 by MEtalGuy66

[candle]

if anyone would be interested, i can post some pictures of those boards

i know there are some other types, but at least those i have

[Kr0tki]

No, I don't remember where I got this listing, but isn't "rev.5" what's in the XEs? And I can definitely verify that there is no PBI support in the IRQ, SIO, CIO, or boot path of this listing.

 

There is some evidence that this listing is divergent from the actual OSes which made it into production use, and that is the "Boot Error" message is in mixed-case rather than all-caps, which is what I see on my XE.

 

Anyone have any insight on the matter?

Basically, all versions after Revision 2 mentioned in this source file, were prototypes that never reached the market. When Tramiels came in, they reverted the OS back to Revision 2 and started shipping the XEs with it. Then the "Rev.3" was created for the later XE machines, and the "Rev.4" for the XEGS - both are descendants from the XL Revision 2.

See also here and here.