Re: MSX2 memory mappers
On Fri, 19 Mar 1999, Alwin Henseler wrote: Ooohh, it's really hard to explain those Brazilians all about memory mappers! (don't they have any?). Not all Brazilians (or am I being so repetitive?). I converted several games from Memory Mapper to Megaram, and I never had Memory Mapper! Some facts: An MSX2 doesn't need to have a memory mapper to be a true MSX-2. Example: Sony HB-G900. 64K RAM, no mapper, but true MSX-2, nothing wrong with it. That's what I said! Sony HB-F9P: 128 K, mapper Smaller: Almost every Japanese-built MSX2 or 2+: 64K mapper Philips NMS 8220 has only 64K, but this IS a mapper. Really a 128K mapper with 2nd half empty, so switching blocks, you get: Block 0, 1, 2, 3, "nothing", "nothing", "nothing", "nothing", block 0 again, 1 again, 2 again, 3 again, "nothing", "nothing", "nothing", "nothing", 0 again, 1 again, etc. Then, it can be expanded to 128kb. Not standard? Absolutely standard! Mapper=64K = 4 blocks (0-3), selecting block 0, 1, 2, 3 gets you mapper blocks 0, 1, 2, 3 - all ok. Reading the mapper ports on this machine would return other values as you might expect, but reading mapper ports SHOULD be considered unreliable, right? Not only unreliable, but a wrong procedure, since the MSX Technical Handbook prevents it. Greetings from Brazil! - Marco Antonio Simon Dal Pozhttp://www.lsi.usp.br/~mdalpoz [EMAIL PROTECTED] "Apple" (c) Copyright 1767, Sir Isaac Newton /"\ \ / CAMPANHA DA FITA ASCII - CONTRA MAIL HTML X ASCII RIBBON CAMPAIGN - AGAINST HTML MAIL / \ MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: MSX2 memory mappers
Nestor's (Konamiman) online version of the MSX-2 technical handbook clearly reads: Well, at least someone is using my TH transcription, nice to see this! 8-) minimum, required: 64 K RAM memory mapper: OPTIONAL Well, actually... I invented this part. X-D Hey, just kidding! - the MSX-2 standard DEFINES memory mappers, but does NOT require it. Yep. In fact, Sony F500 does NOT have memory mapper and does NOT accept external mappers... 15th MSX users meeting in Barcelona: May 1th, 1999 Konami Man - AKA Nestor Soriano (^ ^)v - Itsumo MSX user http://www.geocities.com/SiliconValley/Bay/9797/msx.htm [EMAIL PROTECTED] ICQ#: 18281450 Metal Gear for MSX - (C) Konami 1987 (Nothing new under the sun...) MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: MSX2 memory mappers
"jam" [EMAIL PROTECTED] wrote: You are wrong. Every MSX2 must have Memory Mapper. Even with only 64K of RAM, it's mapped RAM. Read the MSX2 Technical Handbook (by ASCII) and check it. Nestor's (Konamiman) online version of the MSX-2 technical handbook clearly reads: minimum, required: 64 K RAM memory mapper: OPTIONAL - the MSX-2 standard DEFINES memory mappers, but does NOT require it. Alwin Henseler ([EMAIL PROTECTED]) http://huizen.dds.nl/~alwinh/msx MSX Tech Doc page MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
MSX2 memory mappers
Hi all, Ooohh, it's really hard to explain those Brazilians all about memory mappers! (don't they have any?). Some facts: An MSX2 doesn't need to have a memory mapper to be a true MSX-2. Example: Sony HB-G900. 64K RAM, no mapper, but true MSX-2, nothing wrong with it. Apparantly there exist Philips MSX-2's without a mapper (not the 8220, which has a mapper), because I made a schematic once for building 128K mapper in those (if all Philips MSX-2's had mappers, I wouldn't have). I suppose the VG 8230 could be such a machine. If you have a VG8230: check it! Does this one have a mapper, or not? Be sure it is a 8230: I've helped build a 8235 into a 8230's casing once... 128K mappers in Philips machines: Sony HB-F9P: 128 K, mapper Smaller: Almost every Japanese-built MSX2 or 2+: 64K mapper Philips NMS 8220 has only 64K, but this IS a mapper. Really a 128K mapper with 2nd half empty, so switching blocks, you get: Block 0, 1, 2, 3, "nothing", "nothing", "nothing", "nothing", block 0 again, 1 again, 2 again, 3 again, "nothing", "nothing", "nothing", "nothing", 0 again, 1 again, etc. Not standard? Absolutely standard! Mapper=64K = 4 blocks (0-3), selecting block 0, 1, 2, 3 gets you mapper blocks 0, 1, 2, 3 - all ok. Reading the mapper ports on this machine would return other values as you might expect, but reading mapper ports SHOULD be considered unreliable, right? Bigger: Turbo-R: 256K (ST) or 512K (GT), mapper Sony HB-G900AP (note the "A" in there!): 512K or 1 MB., mapper Greetings, Alwin Henseler([EMAIL PROTECTED]) http://huizen.dds.nl/~alwinh/msx MSX Tech Doc page MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: MSX2 memory mappers
Ooohh, it's really hard to explain those Brazilians all about memory mappers! (don't they have any?). Not to ALL brazilian. Just to the "fudeba" ones. :) Adriano Camargo Rodrigues da Cunha ([EMAIL PROTECTED]) Engenharia de Computacao - UNICAMP http://www.adrpage.cjb.net MSX-TR:I have one.And you? *** NEW URL! AdrianPage now is at http://www.adrpage.cjb.net *** * My next Pentium(tm) computer will be a Silicon Graphics Workstation * MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
