NJ_GOKEM%FANDM.BITNET@cornellc.cit.cornell.edu (06/08/90)
>From: edu%"huggard@freezer.it.udel.edu""scott huggard" 7-JUN-1990 18:46:22.67 > >Hello, >According to Amiga World, my 2 month old Amiga 500 may have super agnus >inside... Apparently, you can't tell by the amount of free chip mem >because a jumper must be jumped. >Can anyone tell me how I can check how 'fat' my agnus chip is, >and what are the negative consequenses if I converted my >entire one meg to be chip ram. The AMAX packet comes with a program called CHECKCHIPS. If you run that program it will tell you what kind of agnus you have. So try to find someone with AMAX. If you only have chipram, your computer will be slower, since all data for the 68000 will have to be fetched through Agnus. Especially in hires will it be notecable. If you have fastram, the 68000 can use its databus, at the same time, when Agnus uses its databus to built up the screen, to refresh memory, and to do blitter operations. With no fastmem, you won't use the fastmem databus' capacities. Nils Gokemeijer (NJ_GOKEM@FANDM.bitnet)
uzun@pnet01.cts.com (Roger Uzun) (06/12/90)
>>Nils Gokemeijer writes : With no fastmem you will get more RAM contention
This is only true for REAL FastRAM, not the psuedo-fastram that an Amiga
500 with 512k of expansion mem in the built in trap door is equiipped with.
This pseuodo-fast ram is located at $c00000 and has all the disadvantages
of CHIP RAM (contention with the Custom Chips) but none of the advantages
(it is not accessible by the custom chips). Therefore you lose NOTHING
when you convert your amiga 500 to a 1M CHIP RAM Machine, in fact the
512k of "fast" RAM you used to have was as slow as CHIP RAM to begin with,
so you only gain the advantage of having it accessible by the blitter, etc,
you lose NO speed.
-Roger
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