First post, by assasincz
Hi all,
I am currently refurbishing my best friend's old 486 setup for him, taking this on as a presonal challenge, basically rebuilding it from scratch.
As I am working on the case (retrobrighting, new stickers, overall cleaning), I have the functional HW in sort-of open-bench setup, trying to make it work, I am mostly at the beginning, but already the setup has proven to be quite tricky for me to make it work.
I would therefore like to establish this thread in order to consult with you guys any issue that I stumble across, specific for this setup.
I will skip over the details on the cosmetics (like new CPU fan, new CMOS battery mod).
Currently, the intended list of HW in the setup as follows (CPU and MB are fixed, other components could change):
CPU AMD A80486DX4-120SV8B
MB VEXTREC GMB-486SPS
RAM 4x8MB 72pin SIMM (I have several additional modules of various timings and capacities on hand)
HDD SD-to-IDE adaptor off Ebay with Transcend SDHC 8GB UHS-I 400x Premium (replacing very old and very noisy HDD, plugged on its own to primary on-board IDE channel, and is properly detected)
Video card PCI - undetermined (I have three different S3 PCI VGA cards to chose from)
Sound card ISA - undetermined (I have a SB16, and some ESS ISA cards to chose from)
2x CD-ROM IDE drive (4x speed, 52x speed) plugged to secondary on-board IDE channel
1x FDD 3.5''
PSU Fortron HEXA 400W ATX with ATX-to-AT converter off Ebay
For OS, I would like to eventually have MS DOS 6.22 combined with Windows 95, and option to select the OS to boot on startup (I am not even there, yet)
First thing I did for the actual HW configuration was that I upgraded on-board L2 cache from 256kb to full 1024kB with brand-new chips off Ebay:
8x 128Kx8 DIP32 chips
1x 64K x 8 DIP32 chip (for tag ram)
I have set the jumpers in accordance with the manual, and on-startup full 1024kB L2 cache is correctly detected.
Issue #1 I want to solve is booting; The setup hangs on booting - either from floppy, or HDD of any sort - unless I disable internal cache in BIOS.
This solves the issue and boot-up works fine, but this probably is not the correct way, needing to disable internal cache in BIOS.
Do any of you have any advice what settings (on-board or in-BIOS) I can check and/or change to be able to boot with both internal and external cache enabled?
Issue #2 that leaves me scratching my head - I am trying to make the SD-to-IDE drive work properly. I have partitioned drive using fdisk on my WIN95 start-up diskette, enabled large drive support and the primary partition is set at full 8GB (FAT32, actual capacity is a little less, of course). The drive is accessible but the PC freezes on C:\>dir command, freezes during WIN95 installation scandisk, and C:\>format c: does nothing. What are your suggestions?
Issue #3 what steps do you recommend taking when I want to have a option to select OS on startup - MS DOS 6.22, Windows 95?