Maya Saura 2 

@[email protected]
112 Followers
28 Following
46 Posts

my account dedicated to old computers repairs and analog video shenanigans

my specific interests include:
- bitmap typography and graphic design
- the history of user interfaces
- analog television and phone systems (i live in the country of minitel, sécam and péritel)

my collection include:
- 8-bit: zx81, sega master system, gameboy
- 16-bit: cpc6128, c64, amiga cdtv
- 32-bit: a lot of pc from 486 to p4, sega dreamcast, 68020 accelerated macintosh se, lc, lc475, g3

Website (in french)http://maya.sh
Maya Saura 2 2d ago
the debug post card has the size of a floppy!
Maya Saura 2 4d ago
I found a PS/2 keyboard for my PC! It’s a weird Alcatel MF-II K6356 (exist also with Acer branding). It has Acer-Alps hybrid weird switches with a tactile feeling, it’s satisfying but very light at touch compared to my Apple keyboards with beige or salmon switches. The keyboard itself is light compared to an AEK or Model M. (It’s comparable to an M2.) The box has the date code 06/11/95 but the keyboard don’t have the Windows key.
Maya Saura 2 Apr 23

it's the creative ct6950 variant

the graphic card works only in the bios and in dos:
- when trying to boot windows, i only have a blinking cursor
- vmtce crashes the computer
- checkit vram test shows multiple errors (but the graphic mode test patterns are fine)

also:
- the video bios display a text screen at boot
- there is no graphic corruption

after replacing the 70W PSU of the computer by a 300W one from another computer i have this behavior:
- windows still don't boot
- vmtce crashes with an error message related to memory and returns to dos prompt
- checkit vram test still shows errors but less

after using the 300W PSU only for the motherboard and using the 70W one for the hard drive i have this behavior:
- windows try to boot but fails saying some file is missing (it's not true)
- vmtce works and can test vram (no error)
- checkit vram test is now good

i measured the voltage on one of the 2 regulators on the board (RC1587M), it receives a 3V input and outputs 1.5V  ; there is another regulator that i did not test (AMS1505)

after that i desoldered the electrolytic capacitors: the 2 big 330uF are good (measured 360~) but the others (6x10uF and 3x22uF) are all bad 

Maya Saura 2 Apr 21
i replaced the 350 MHz AMD-K6-2 cpu by a 500 in my aptiva 2158, the ibm documentation doesn't include the switch configuration for this frequency but the original documentation of the motherboard (acer v72ma) does ! i also replaced the old thermal pad by thermal paste and the computer boots without any issue on the aptiva bios!
Maya Saura 2 Apr 15

i have a modem to match with my computer! it's a french "olitec speedcom 56000" but with a blue shell and a Wanadoo branding! Wanadoo was the internet service of France Télécom before it became Orange.

It's a "no screw" design, the back panel slides out and reveal the speaker and 2 pcbs connected to each others by a connector and rivets (??)

i managed to identify these chips inside:
- RCVDL56ACFW/SP modem
- LBA120 dual relay
- CY7C1009 1 MB SRAM
- AM29F002BT-90JC 2 MB flash memory
- MC74HCT08A quad AND gate
- MC74HCT157AD quad 2 input multiplexer

Show threadMaya Saura 2 Apr 14
i found these speakers in my basement, it's perfect to play MIDI files 
Maya Saura 2 Apr 13
Microsoft Dinosaurs had a textured titlebar!
Show threadMaya Saura 2 Apr 10

today i've done a lot of cleaning and removed a lot of dust in the aptiva case!

i've also tested different ram sticks i had in a box and polished some of them that were not detected with a dremel (it worked)    i found another 64MB PC100 to add in this computer

the power supply was completely disassembled and cleaned, it was difficult to reassemble it! the capacitors inside are fine. the fan is much less noisy without this dead bee inside  i plugged it in another pc and the bios reports +5.1V, +11.9V and -12.1V  

i have reassembled the computer with a 20 GB hard drive and a random working cd drive and i'm now installing windows, i will add expansion cards and test my 3dfx later

Show threadMaya Saura 2 Apr 9

i will check the power supply later, i tried to run the computer with a known good psu and it boots fine to a startup dos floppy :)

but the bios setup is in italian and i can't change it in the menu, maybe it's possible in the flash utility - the board is an acer v72ma referenced in "the retro web" and there is a "upgrade disk image" for ibm variant

Show threadMaya Saura 2 Apr 9

all parts are original with the exception of the cd drive, i've tested the different parts on another computer:
- the hard drive is broken, it's making clicky noise
- the ram stick (64 MB PC100) works
- the cd drive operates mechanically but the bios don't recognize it ("atapi incompatible" error)
- the psu works but the fan make a weird noise and the 12V rail is more like 11V  

the hard drive and floppy are in a rotational caddy, really easy to disassemble!