8.10) What kinds of extra RAM and RAMdisks can be installed?

Subject: 8.10) What kinds of extra RAM and RAMdisks can be installed?

This section by Andreas Magenheimer.

(Version 3.5 from January 2004 by A.M.)

A) Atari 400/800 Ramdisks:

- Size: 64k XRAM (+ 32k RAM)
Banks: 0 thru 3 (total memory = 96k RAM)
Types: Axlon (=Atari) and compatibles;

- Size: 128k XRAM (+ 32k RAM)
Banks: 0 thru 7 (total memory = 160k RAM)
Types: Axlon (= Atari) and compatibles;

- Size: 256k XRAM (+ 32k RAM)
Banks: 0 thru 15 (total memory = 288k RAM)
Types: D. Byrd and other selfmade / Axlon-compatible RDs;

- Size: 512k XRAM (+ 32k RAM)
Banks: 0 thru 31 (total memory = 544k RAM)
Types: selfmade / Axlon-compatible Ramdisks;

- Size: 1024k XRAM (+ 32k RAM)
Banks: 0 thru 63 (total memory = 1056k RAM)
Types: selfmade / Axlon-compatible Ramdisks;

- Size: 2048k XRAM (+ 32k RAM)
Banks: 0 thru 127 (total memory = 2080k RAM)
Types: selfmade / Axlon-compatible Ramdisks;

- Size: 4096k XRAM (+32k RAM)
Banks: 0 thru 255 (total memory = 4128k RAM)
Types: selfmade / Axlon-compatible Ramdisks;

=> Note that all so-called Axlon "compatible" (256k-4096k) Ramdisks
normally do not homebank when RESET is pressed (a fix should be
available somewhere), whereas original Axlon Ramdisks do homebank
properly !! (Special thanks to Lee Barnes for this note !!)

B) XL/XE - 64k base RAM plus XRAM:

- Size: 64k (total = 128k RAM, 4 banks)
- Banks: E3, E7, EB, EF (block E = 1 block * 4 banks)
- Types: 130XE-Ramdisk, Turbo-Freezer-XL + 64k, selfmade-ramdisks...

- Size: 128k (total = 192k RAM, 8 banks)
- Banks: A3,A7,AB,AF,E3,E7,EB,EF
(blocks AE = 2 blocks * 4 banks)
- Types: Compyshop 600XL with 192k, Turbo-Freezer-XL + 128k,
selfmade-RDs...

- Size: 256k / 26AE (total = 320k RAM, 16 banks)
- Banks: 23,27,2B,2F,63,67,6B,6F,A3,A7,AB,AF,E3,E7,EB,EF
(blocks 26AE, = 4 blocks * 4 banks)
- Types: Compyshop 800XL RD., Compyshop 130XE RD.,
Peters/David Megaram 1, Peters/David Megaram 2,
Peters/David Megaram 3 with 256k, selfmade RDs...

- Size: 256k / 8ACE (total = 320k RAM, 16 banks)
- Banks: 83,87,8B,8F,A3,A7,AB,AF,C3,C7,CB,CF,E3,E7,EB,EF
(blocks 8ACE = 4 blocks * 4 banks)
- Types: Newell, Rambo-XL, Scott Peterson, Atari Magazin,
TOMS, selfmade-RDs...

- Size: 512k / 26AE (total = 576k RAM, 32 banks)
- Banks: 21,23,25,27,29,2B,2D,2F,61,63,65,67,69,6B,6D,6F,
A1,A3,A5,A7,A9,AB,AD,AF,E1,E3,E5,E7,E9,EB,ED,EF
(blocks 26AE = 4 blocks * 8 banks)
- Types: none (that I know of) at the moment - but possible!

- Size: 512k / 8ACE (total = 576k RAM, 32 banks)
- Banks: 81,83,85,87,89,8B,8D,8F,A1,A3,A5,A7,A9,AB,AD,AF,
C1,C3,C5,C7,C9,CB,CD,CF,E1,E3,E5,E7,E9,EB,ED,EF
(blocks 8ACE = 4 blocks * 8 banks)
- Types: Scott Peterson, TOMS, selfmade-RDs...

- Size: 512k / 02468ACE (total = 576k RAM, 32 banks)
- Banks: 03,07,0B,0F,23,27,2B,2F,43,47,4B,4F,63,67,6B,6F,
83,87,8B,8F,A3,A7,AB,AF,C3,C7,CB,CF,E3,E7,EB,EF;
(blocks 02468ACE = 8 blocks * 4 banks)
- Types: 1) upgrade / combination of 26AE and 8ACE ramdisk
types to 512k RAM or to *one* 02468ACE ramdisk;
idea by me, built by Bernhard Pahl (see his homepage
at http://www.b-pahl.de/atari8bit/ramdisk)
2) Upgrade of the Rambo XL to 512k by Dan Schmid
(see Pooldisk Too, Subdir ACE/ Acec202a.ATR and
Acec202b.ATR) and of course 3) selfmade ramdisks...

- Size: 1024k / 02468ACE (total = 1088k RAM, 64 banks)
- Banks: 01,03,05,07,09,0B,0D,0F,21,23,25,27,29,2B,2D,2F
41,43,45,47,49,4B,4D,4F,61,63,65,67,69,6B,6D,6F
81,83,85,87,89,8B,8D,8F,A1,A3,A5,A7,A9,AB,AD,AF
C1,C3,C5,C7,C9,CB,CD,CF,E1,E3,E5,E7,E9,EB,ED,EF
(blocks 02468ACE = 8 blocks * 8 banks)
- Types: Newell, Scott Peterson, TOMS, Satantronic`s 1MB-
PC-SIMM-RD, selfmade-RDs...

- Size: 1024k / 26AE (total = 1088k RAM, 64 banks)
- Banks: EF,EE,ED,EC,EB,EA,E9,E8,E7,E6,E5,E4,E3,E2,E1,E0
AF,AE,AD,AC,AB,AA,A9,A8,A7,A6,A5,A4,A3,A2,A1,A0
6F,6E,6D,6C,6B,6A,69,68,67,66,65,64,63,62,61,60
2F,2E,2D,2C,2B,2A,29,28,27,26,25,24,23,22,21,20
(blocks 26AE = 4 blocks * 16 banks)
- Types: Mathy van Nisselroy`s 1024k XEGS-PC-SIMM-Upgrade!
(with some changes probably also usable for XL and XE,
see also: http://www.mathy-van-nisselroy.nl)

- Size: 1024k / 8ACE (total = 1088k RAM, 64 banks)
- Banks: EF,EE,ED,EC,EB,EA,E9,E8,E7,E6,E5,E4,E3,E2,E1,E0
CF,CE,CD,CC,CB,CA,C9,C8,C7,C6,C5,C4,C3,C2,C1,C0
AF,AE,AD,AC,AB,AA,A9,A8,A7,A6,A5,A4,A3,A2,A1,A0
8F,8E,8D,8C,8B,8A,89,88,87,86,85,84,83,88,81,80
(blocks 8ACE = 4 blocks * 16 banks)
- Types: none (that I know of) at the moment - but possible!

- Size: 1024k / 0123456789ABCDE (total = 1088k RAM, 64 banks)
- Banks: blocks 0123456789ABCDE each with 4 banks
= 16 blocks * 4 banks (does not make much sense, but...)
- Types: luckily, none at the moment...

- Size: 1024k / ??? (max. memory = 1088k, 64 banks)
- Port-Bits / Control-Bits: $D301 = 2,3,6,7
$D600 = 0,1 (or switches);
- Banks: $D301: 23,27,2B,2F,63,67,6B,6F,A3,A7,AB,AF,E3,E7,EB,EF
$D600: F3,F7,FB,FF...
- Types: David/Peters Megaram 3 with 1024k RAM (and the switches
positioned to 1 x 1024k)

- Size: 2048k / 02468ACE (total = 2112k, 128 banks)
- Banks: 00,01,02,03,04,05,06,07,08,09,0A,0B,0C,0D,0E,0F
20,21,22,23,24,25,26,27,28,29,2A,2B,2C,2D,2E,2F
40,41,42,43,44,45,46,47,48,49,4A,4B,4C,4D,4E,4F
60,61,62,63,64,65,66,67,68,69,6A,6B,6C,6D,6E,6F
80,81,82,83,84,85,86,87,88,89,8A,8B,8C,8D,8E,8F
A0,A1,A2,A3,A4,A5,A6,A7,A8,A9,AA,AB,AC,AD,AE,AF
C0,C1,C2,C3,C4,C5,C6,C7,C8,C9,CA,CB,CC,CD,CE,CF
E0,E1,E2,E3,E4,E5,E6,E7,E8,E9,EA,EB,EC,ED,EE,EF
(blocks 02468ACE = 8 blocks * 16 banks)
- Types: selfmade-Ramdisks...

- Size: 2048k / 0123456789ABCDEF (total = 2112k, 128 banks)
- Banks: 01,03,05,07,09,0B,0D,0F,11,13,15,17,19,1B,1D,1F,
21,23,25,27,29,2B,2D,2F,31,33,35,37,39,3B,3D,3F,
41,43,45,47,49,4B,4D,4F,51,53,55,57,59,5B,5D,5F,
61,63,65,67,69,6B,6D,6F,71,73,75,77,79,7B,7D,7F,
81,83,85,87,89,8B,8D,8F,91,93,95,97,99,9B,9D,9F,
A1,A3,A5,A7,A9,AB,AD,AF,B1,B3,B5,B7,B9,BB,BD,BF,
C1,C3,C5,C7,C9,CB,CD,CF,D1,D3,D5,D7,D9,DB,DD,DF,
E1,E3,E5,E7,E9,EB,ED,EF,F1,F3,F5,F7,F9,FB,FD,FF;
(blocks 0123456789ABCDEF = 16 blocks * 8 banks)
- Types: selfmade-Ramdisks...

- Size: 4096k / 0123456789ABCDEF (total = 4160k, 256 banks)
- Banks: 00,01,02,03,04,05,06,07,08,09,0A,0B,0C,0D,0E,0F
10,11,12,13,14,15,16,17,18,19,1A,1B,1C,1D,1E,1F
20,21,22,23,24,25,26,27,28,29,2A,2B,2C,2D,2E,2F
30,31,32,33,34,35,36,37,38,39,3A,3B,3C,3D,3E,3F
40,41,42,43,44,45,46,47,48,49,4A,4B,4C,4D,4E,4F
50,51,52,53,54,55,56,57,58,59,5A,5B,5C,5D,5E,5F
60,61,62,63,64,65,66,67,68,69,6A,6B,6C,6D,6E,6F
70,71,72,73,74,75,76,77,78,79,7A,7B,7C,7D,7E,7F
80,81,82,83,84,85,86,87,88,89,8A,8B,8C,8D,8E,8F
90,91,92,93,94,95,96,97,98,99,9A,9B,9C,9D,9E,9F
A0,A1,A2,A3,A4,A5,A6,A7,A8,A9,AA,AB,AC,AD,AE,AF
B0,B1,B2,B3,B4,B5,B6,B7,B8,B9,BA,BB,BC,BD,BE,BF
C0,C1,C2,C3,C4,C5,C6,C7,C8,C9,CA,CB,CC,CD,CE,CF
D0,D1,D2,D3,D4,D5,D6,D7,D8,D9,DA,DB,DC,DD,DE,DF
E0,E1,E2,E3,E4,E5,E6,E7,E8,E9,EA,EB,EC,ED,EE,EF
F0,F1,F2,F3,F4,F5,F6,F7,F8,F9,FA,FB,FC,FD,FE,FF
(blocks 0123456789ABCDEF = 16 blocks * 16 banks)
- Types: Newell, FTE, selfmade-Ramdisks...

Well, I will not go into details with the disadvantages and
software-problems with ramdisks beyond 512k RAM (Selftest, XL/XE Basic,
RAM under the OS, separate Antic access, etc.). These problems mostly
occur with 1 Megabyte or bigger ramdisks and there are several hardware
and software solutions for them, alas not working correct with every
software or program. With 4 Megabyte extra RAM / Ramdisk, the PIA is
fully used/adressed, so that normally the base RAM at 4000-7FFF is not
available any longer. But again, there are tricks and solutions to solve
this problem. Installing a second PIA for example makes it possible to
adress up to 256 Megabytes of extra RAM / Ramdisk - but who needs so much
RAM on the Atari 8Bit computer ???

C) XL/XE - XRAM minus 64k Base-RAM:

- Size: 192k / 8AE (total = 256k RAM, usable = 12 banks)
- Banks: 83,87,8B,8F,A3,A7,AB,AF,E3,E7,EB,EF
(8AE = 3 blocks * 4 banks)
- Types: older Newell ramdisks (replace 64k by 256k);

- Size: 192k / ACE (total = 256k RAM, usable = 12 banks)
- Banks: A3,A7,AB,AF,C3,C7,CB,CF,E3,E7,EB,EF
(ACE = 3 blocks * 4 banks)
- Types: newer Newell RDs, newer Buchholz-RDs, Rambo-XL,
selfmade Ramdisks (replace 64k by 256k)...

- Size: 448k / 2468ACE (total = 512k, usable = 28 banks)
- Banks: EF,EB,E7,E3,CF,CB,C7,C3,AF,AB,A7,A3,8F,8B,87,83
6F,6B,67,63,4F,4B,47,43,2F,2B,27,23
(2468ACE = 7 blocks * 4 banks)
- Types: selfmade-RDs (replace 64k by 512k)...

- Size: 896k? / 0248ACE (total = 1024k, usable = 56 banks)
- Banks: EF,ED,EB,E9,E7,E5,E3,E1,CF,CD,CB,C9,C7,C5,C3,C1,
AF,AD,AB,A9,A7,A5,A3,A1,8F,8D,8B,89,87,85,83,81,
4F,4D,4B,49,47,45,43,41,2F,2D,2B,29,27,25,23,21,
0F,0D,0B,09,07,05,03,01 (0248ACE = 7 blocks * 8 banks)
- Types: Bob Woolley`s 1200XL 1MB Upgrade, selfmade-RDs
(replace 64k by 1024k)...

Allthough these RAM upgrades are relatively easy to build
(and to install into the computer), they make problems with
quite some software. Some programs tend to use the base RAM
as extra RAM / Ramdisk with these upgrades, which will most
often result in a crash of the computer. Next, most extra RAM
testers will show more extra RAM (or a bigger Ramdisk) than
there is really available (e.g. with a 256k upgrade you will
see 240k extra RAM, but there is only 64k base RAM + 192k
extra RAM). Alas, this is a typical hardware problem for these
upgrades and it cannot be solved or avoided with software...

D) XL/XE: Parallel-Bus-Devices:
(600XL/800XL = Parallel Bus, XE = Cart.-Port + ECI)

- Size: 64k / E (total = 128k RAM, 4 banks)
- Banks: E3,E7,EB,EF (block E = 1 block * 4 banks)
- Types: Turbo-Freezer-XL by Bernhard Engl with 64k XRAM

- Size: 128k / AE (total = 192k RAM, 8 banks)
- Banks: A3,A7,AB,AF,E3,E7,EB,EF (blocks AE = 2 blocks * 4 banks)
- Types: Turbo-Freezer-XL by Bernhard Engl with 128k XRAM

- Size: 256k / 9ABE (total = 320k RAM, 16 banks)
- Banks: 93,97,9B,9F,A3,A7,AB,AF,B3,B7,BB,BF,E3,E7,EB,EF
(blocks 9ABE = 4 blocks * 4 banks)
- Types: Turbo-Freezer-XL by Bernhard Engl with 256k XRAM

- Size: 256k / ??? (total = 320k RAM, 16 banks)
- Banks: unknown !!
- Types: Yorky-XL by Richard Gore / Derek Fern (from
GB/UK) with 256k XRAM

- Size: 256k / ??? (total = 320k RAM, 16 banks)
- Banks: unknown !!
- Types: Multi-Input-Output-Harddisk-Interface (MIO) with 256k
XRAM by ICD

- Size: 1024k / ??? (total = 1088k RAM, 64 banks)
- Banks: unknown !!
- Types: Multi-Input-Output-Harddisk-Interface (MIO) with 1024k
XRAM by ICD

E) XL/XE: RAM/Flash-ROM/... Cartridges:

- Rambox II with 256k RAM by JRC (Czech Republic; with special
Ramdisk drivers for TT-DOS and Bewe-DOS!)
- Ramcart 64k by LK Avalon (Poland)
- Ramcart 128k by LK Avalon (Poland; binaries of the Eprom and GAL
chips of this cart can be found on ABBUC magazine 64)
- Ramcart 256k by Zenon/Dial (Poland)
- Ramcart 512k by Zenon/Dial (Poland)
- Ramcart 1024k by Zenon/Dial (Poland)
(for some hints and pics see: www2.asw.cz/~kubecj/acarts.htm)
- Flash-ROM cart 128k / 1Mbit "Atarimax" by Stephen Tucker
(allthough they are not usable as extra RAM / Ramdisk at the moment,
I am quite sure that it is possible to write some drivers and thus
use the Atarimax Flash-ROM carts as extremely fast floppy drives!)
- Flash-ROM cart 1024k / 8Mbit "Atarimax" by Stephen Tucker
(for information and complete documentation plus software see:
www.atarimax.com/flashcart/documentation/index.html )
- and many others I do not know and I do not have any info about;

Even cartridges can be used as Ramdisks (= fast floppy drives),
especially RAM-carts or Flash-RAM carts. But they function like
most other Super- or Mega-Carts, meaning the bank-switching
techniques are also used there. Since the subject carts and
bank-switching carts is quite enormous, I will not discuss it or
present any information here. Just try to find a large description
by John K. Picken ("RAM/ROM Control on an XL/XE") if interested in that
subject (e.g. at Jindrich Kubec`s homepage: www2.asw.cz/kubecj/... ).

Finally thanks and credits for this subject and lots of (used /
borrowed) information therefore go to: Lee Barnes, Russ Gilbert,
Mathy van Nisselroy, Erhard Puetz, Mathias Reichl, Ron Hamilton,
Wes Newell, Guy Ferrante, XI of Satantronic, Bernhard Pahl, Walter
Lojek and Voy/Dial. Also thanks to John K. Picken who wrote an
excellent article about A8 extra RAM / Ramdisks and A8 cartridges and
their technique of bank-switching. Well, if you still find errors, bugs,
mistakes, etc. in this list, then tell me *nicely* or in a friendly
way. Any updates and corrections can be send to: amp@abbuc.de
-Andreas Magenheimer