Blizzard 1230/IV jumpers
 

I bought a Blizzard 1230/IV acelerator with 16MB of ram according to the seller but my A1200 only detects 8mb of ram.My question is:should be a jumper placed to detect the 16MB of ram?and in which position?

Thanks in advance:)

No jumper setting is required to detect the size of any ram memory (up to 128 MB).

The 2 jumpers are for:
a) 60 ns / 70 ns speed memory
b) to move kickstart ROM to RAM memory. Your Amiga will be about 5% faster losing 512 KB RAM.

A PDF manual for the Blizzard 1230/IV should be available somewhere.

I fear the RAM your Amiga detects is the real size. Sorry.

Thanks mate!:great

I have the manual physical but only explains how to install the device kit SCSCI.

fc.studio is right... is it possible you have been given an 8mb ram stick?
Can you take a picture of the ram stick and post it here?

Here a link to a Blizzard 1230/IV user manual, PDF format, german/english.

http://phase5.a1k.org/files/1230iv.pdf

I used the map rom jumper for a while, until i found out some WHDLoad games whould crash more often, even exchanged the ram simm and all, same thing.:guru

@Yoto

Any specific games you can mention? What OS setup do you have? (and many patches?)
You saying that some whdload games still crash even with maprom off, but crash more often (?) with it on?

@OP
Maybe try with 70ns setting. Although I would most likely think the seller was mistaken esp if it is the same ram they were running it with.

Hi you guys,

Ive a blizzard 1230 IV, and i recently bought myself a 128mb dimm, exactly like this one here: http://www.ebay.com/itm/181231652890...&sojTags=bu=bu
My problem its that only detects 32mb ram, instead of the total 128mb :confused

What could be the problem? ive read in the manual that the memory latency should be 60ns or better, mine is 50ns, any of you guys successfully tested a 50ns module on your accelerator?
Do i have to change any jumpers for total memory detection?

No, there are no jumpers required - it's already mentioned above.

I had a 16MB SIMM in mine, then exchanged it for a 128MB SIMM, changed nothing and it just worked.

It sounds like you either have a defective SIMM, or it was mis-labelled?

Manual moved locations: http://phase5.a1k.org/filearchive/1230iv.pdf

Yep, it autodetects. It's possible that there is some contact issue and you're missing some address lines to the SIMM through tarnishing etc., but most likely a SIMM defect.

@Mr.Flibble @Daedalus
Thanks for your answers, by the way the image below is my simm, can you guys confirm that it has the correct specs?

https://s21.postimg.org/97aronfs7/IMG_0884.jpg

I can't read the part numbers off the chips in that photo - could you quote them please? Just off one chip, they should all be identical.

hyundai
GM71V65403CT5

any help from someone will be very much appreciated

Yep, those chips are 8MB each (16MWords x 4bit), so presuming the same chips are on the other side of the SIMM, that's 8MB x 16 chips = 128MB. So it's correctly labelled anyway. Looks like there's some fault with the connections, the SIMM, one of the chips on the SIMM or the accelerator. Check the SIMM socket for any damage to the pins, clean any tarnish off the contacts on the socket and the SIMM, and see if there looks like there's any damage to the SIMM or accelerator PCBs. I would expect there's some failure on one of the select lines causing higher parts of the memory to "disappear".

50ns SIMMS should work just fine, they're generally quite happy to be underclocked by a fair amount.