First post, by Gonduron
- Rank
- Newbie
While building a high-end 486 retro-PC, I tripped over a L2-cache / SRAM DIP problem.
System:
- I've got an Asus VL-I-486SV2GX4 mainboard.
- This mainboard came with eight pre-installed SRAM chips, 28-pins, 256 kByte Cache in total. Type is Winbond W24257AK-15, see datasheet attached.
- These DIPs work all ok.
Target:
- I want to upgrade to 1 MByte L2-cache total. I guess this won't give me a big boost; it's really just for the look and feel 😀
Problem:
- I bought SRAM chips from a trustworthy UK vendor (The Micro Hut): Eight DIPs, 32-pins, type is ISSI IS61C1024-15N, see datasheet attached.
- I installed the chips in proper orientation and set the mainboard jumpers for 1 MByte total as written in the manual.
- Unfortunately, this did not work. At power-on black screen, no POST beep.
Troubleshooting:
- I reverted to the 256 kByte setup. System now works ok again.
- I compared the datasheets of both SRAM chips: The ISSI chips have a different pinout 🙁
- I googled around and found a potentially suitable SRAM DIP, type Winbond W241024AK-15, see datasheet attached.
- Even though the pinout is almost the same, it does not match 100%: On the small Winbond chip pin28 is VDD (power supply), whereas on the big Winbond chip the same pin is CS2 (chip select).
Question:
1) Any idea whether the big Winbond chip will work or not?
2) Will the Mainboard jumpers take care of the slightly different pinout (VDD-pin on MB into CS-pin of SRAM)?
3) Do you know of any 1024k DIPs that will definitely work with this mainboard?
Thank you for your time 😀
My "Pixeli": Intel 486DX4-100 -- Asus VL/I-486SV2GX4 -- 16 MB -- Diamond Stealth64 S3 Vision868 2 MB VLB -- AWE64 Gold -- Roland LAPC-I and SCC-1 -- Adaptec AVA-2825 -- IBM 1 GB SCSI-2 -- Plextor 8x -- Teac 3,5" + 5,25" -- EIZO S2133