| Re: [hatari-devel] About RAM size comments (commit 6c827e5) |
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- To: hatari-devel@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [hatari-devel] About RAM size comments (commit 6c827e5)
- From: Christian Zietz <czietz@xxxxxxx>
- Date: Sat, 2 Jan 2021 17:13:53 +0100
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Eero Tamminen schrieb:
The comments that state it to be max, mean that
given amount is max for those machine types:
- 10MB: max for MegaSTE & TT (due to VME)
- 14MB: max for Falcon
AFAIK they don't support more ST-RAM even with
HW modifications...?
> Then why is the MegaSTE mentioned in the comments for 8 MB and 10 MB?
Why MegaSTE wouldn't support 8MB, when max is 10MB?
One has to distinguish between two things:
- All machines with "ST" in their name (ST, MegaST, STE, MegaSTE) are
limited to 4 MB of ST-RAM because of their MCU design.
- If you design a new MCU IC, you can fill the entire unused address
space with ST-RAM, which means 10 MB on the MegaSTE (because VME starts
at $A00000), 14 MB on the STE, 14 - 15 MB on the ST/MegaST (depending on
whether you want to support TOS 2 ROMs).
So, yes, with a newly designed MCU, the MegaSTE would support 8 MB. But
so would the ST, MegaSTE, and STE. Hence, why does the comment for 8 MB
specifically mention the MegaSTE, when it is no different from the other
STs in that regard?
Regards
Christian
--
Christian Zietz - CHZ-Soft - czietz@xxxxxxx
WWW: https://www.chzsoft.de/
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