scott@uwav1.u.washington.edu (02/08/91)
In article <1429@tau.sm.luth.se>, d90-pan@sm.luth.se (Per Andersson) writes: > > I own a 1764 REU and I've heard that you can upgrade it to as much as > 2Mb of RAM. > My questions are: > > - Is this really true ? Yes, this is very much true. There are places that will do this upgrade in memory. There is also a text file in Milton-FTP site describing the procedure on how to add more memory to the 1764 for those do-it-yourselvers. It is located in subdirectory: "public/download/c64/info-ideas-projects". > - Can GEOS take advantage of this amount of memory ( I have GEOS > V1.3 ) ? How ? Definately. There are configuration files for GEOS that will that full advantage of larger memory size, like creating a 1581 ramdrive and shawdow drives. Also there are applications like GeoWizards that requires the larger memory size. With GeoWizards, you can jump back and forth from one application to another and back without closing it. > - How can I get this memory expansion ( I live in Sweden ) ? Do it yourself (see above). Or mail it to a company that do this expansion. > - What about compatibility whith the "unexpanded" 1764 ? It is still fully compatible. > Thanks in advance. > > | Per Andersson | c/o Boman | Voice natl. 0920 - 164 47 | > | University of Luleaa | Kungsgatan 16 | intl. +46 920 164 47 | > | SWEDEN | S-951 32 Luleaa | Internet: d90-pan@sm.luth.se | Sincerely, Scott K. Stephen
treesh@vangogh.helios.nd.edu (02/08/91)
I have self-expanded my 1700 to a 1750 clone. This expanded unit works great for me for what I use my REU for, but I dont use it with GEOS. My REU works as a "Ram drive with out a device number" as quoted from my software manual. There is a driver file on the software that I am running, wich is C-Net 129 v5.0. The software runs in C128 mode, mostly in Basic 7.0 for the most part, but the REU stuff is in ML. If I where to get my REU expanded to 1 or 2 megs of ram, would I be able to access it via Basic 7.0, or would speical driver software be needed? ctfm
rknop@nntp-server.caltech.edu (Robert Andrew Knop) (02/09/91)
treesh@vangogh.helios.nd.edu writes: >I have self-expanded my 1700 to a 1750 clone. This expanded unit works great >for me for what I use my REU for, but I dont use it with GEOS. My REU works >as a "Ram drive with out a device number" as quoted from my software manual. >There is a driver file on the software that I am running, wich is C-Net 129 >v5.0. The software runs in C128 mode, mostly in Basic 7.0 for the most >part, but the REU stuff is in ML. If I where to get my REU expanded to >1 or 2 megs of ram, would I be able to access it via Basic 7.0, or would >speical driver software be needed? Yes, it will work, but will you be able to take advantage of the >512K memory is another question. My guess would be no, but it depends on how the program is written. The means of accessing expanded REU's is a direct logical extention of the means of accessing the first 512K. However, there is a single bit flag in the I/O block, which is set off for a 1700, on for a 1750. Most programs probably will test this flag, see that it is on, and think that they have only 512K of expanded RAM, when really they could get at as much as 1.5 Meg more without any need to resort to programming tricks (you simply ask the computer to load from a higher address in the REU, same exact procedure as for low addresses in the REU). Some programs, e.g. GEOS with Configure2.1, explicitly test your REU, by trying to write/read from each 64K bank, to figure out how much expanded memory there is. It would be nice if all programs operated this way, but... well, that's always how it is with new hardwrae. -Rob Knop rknop@tybalt.caltech.edu
treesh@bach.helios.nd.edu (02/10/91)
My software can tell the difference between the 1700/1764 and the 1750 REU's automatically. Perhaps it could then tell the difference between a 1750 at 512K and a 1750 at 2 megs. I guess the only way is to try it. ctfm