BloodyCactus
Experienced Member
Was messing around with restoring the SX today, I upped the ram to 640kb. I sort of knew, but didn't connect, that it steals 16kb of ram for video. Its funny to see text mode ram mapped at 0x9C00 and 0xB800!
I did notice that some of my apps fail, and I found that I am looking at 0x40:84 for the number of lines on the screen, so I had to write a 9 byte com that put 0x18 there and stick in my autoexec.bat, then everything is good. I ended up bugfixing my micro ansi driver to deal with it.
and wow, with the keyboard protocol being much faster than AT/PS2 protocol... the shifted keys are a PITA.. and the layout of where the \ is, I keep hitting print and locking the system out. doh...
Changing dipswitch 2 (which should toggle irq 2/5 to 5/2 between video + disk), if I set this and run Check It, it will say IRQ7 use by LPT1... if I flip it back, and run it again I get IRQ7 free, LPT1 not in use... SW2 should have no bearing on LPT1!! its so wierd.
toggling SW1 should change from CGA to Composite, yet nothing happens, maybe things autodetect and it stays on CGA mode when it boots.
Since this SX came from an engineer, it of course has a GPIB card with 8kb ram sitting up not being used so I wrote a tool to map that ram into the dos MCB chain which is nice, extra 8kb non-contiguous ram!
I forgot how bad dos 3.3 was
vs dos6
psu fan is loooooooooooouuuuuuuuud! Gonna have to replace that before I bolt everything back together.
aaand latching switch on my 1902A just died and stopped latching. sigh.
somehow need to pull the fastcard iv drivers off the nasty 30mb rll fake 20mb miniscribe drive and get them onto my xt-cf-lite.. thats going to be some fun.
ooh only 1 free dma channel.. 3com nic wants it. soundlbaster wants it. this will be an interesting fight!
I dumped my utils temporarily up at https://kråketær.com/stuff.zip if anyone is interested.
adds a few more things to the todo list.
I did notice that some of my apps fail, and I found that I am looking at 0x40:84 for the number of lines on the screen, so I had to write a 9 byte com that put 0x18 there and stick in my autoexec.bat, then everything is good. I ended up bugfixing my micro ansi driver to deal with it.
and wow, with the keyboard protocol being much faster than AT/PS2 protocol... the shifted keys are a PITA.. and the layout of where the \ is, I keep hitting print and locking the system out. doh...
Changing dipswitch 2 (which should toggle irq 2/5 to 5/2 between video + disk), if I set this and run Check It, it will say IRQ7 use by LPT1... if I flip it back, and run it again I get IRQ7 free, LPT1 not in use... SW2 should have no bearing on LPT1!! its so wierd.
toggling SW1 should change from CGA to Composite, yet nothing happens, maybe things autodetect and it stays on CGA mode when it boots.
Since this SX came from an engineer, it of course has a GPIB card with 8kb ram sitting up not being used so I wrote a tool to map that ram into the dos MCB chain which is nice, extra 8kb non-contiguous ram!
I forgot how bad dos 3.3 was
vs dos6psu fan is loooooooooooouuuuuuuuud! Gonna have to replace that before I bolt everything back together.
aaand latching switch on my 1902A just died and stopped latching. sigh.
somehow need to pull the fastcard iv drivers off the nasty 30mb rll fake 20mb miniscribe drive and get them onto my xt-cf-lite.. thats going to be some fun.
ooh only 1 free dma channel.. 3com nic wants it. soundlbaster wants it. this will be an interesting fight!
I dumped my utils temporarily up at https://kråketær.com/stuff.zip if anyone is interested.
adds a few more things to the todo list.