Calab Posted May 10, 2022 Share Posted May 10, 2022 Looking at adding something to the empty U36 socket on my flat C128. Not really sure what is available and worthwhile to put into this socket these days. Google is turning up a few old posts, but nothing recent. What is available to burn to an EPROM for U36? Which EPROM should be used here? My C128 is connected to a Pi1541 and a read 1571 drive and printer interface. This C128 also has JiffyDOS installed, but I don't have the original ROM that should have been installed in U35. Is the same EPROM type as what goes into U36? Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted May 11, 2022 Share Posted May 11, 2022 The socket supports 32k (27C256 IIRC) and there are a plethora of expansions to go here: BASIC8, Servant 128, GEOS 128 v2, among others. There have been a few multi-ROMs over the ages which contain four or more of the various utilities. The U35 ROM is 16k, which would be a 27C128. But your JiffyDOS ROM should be switchable so the original Kernal can be used. If it is on a riser, then it likely is. Quote Link to comment Share on other sites More sharing options...
+eebuckeye Posted May 11, 2022 Share Posted May 11, 2022 How do you select roms when booting? Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted May 11, 2022 Share Posted May 11, 2022 51 minutes ago, eebuckeye said: How do you select roms when booting? Depends upon the ROM. By default, with the proper header, the ROMs will automatically start. However, many have been revamped, especially the multi-ROMs, to allow you to bypass or to bring up a menu. Quote Link to comment Share on other sites More sharing options...
Calab Posted May 11, 2022 Author Share Posted May 11, 2022 10 hours ago, OLD CS1 said: The socket supports 32k (27C256 IIRC) and there are a plethora of expansions to go here: BASIC8, Servant 128, GEOS 128 v2, among others. There have been a few multi-ROMs over the ages which contain four or more of the various utilities. The U35 ROM is 16k, which would be a 27C128. But your JiffyDOS ROM should be switchable so the original Kernal can be used. If it is on a riser, then it likely is. There is no physical hardware to switch my JiffyDOS ROM out... Looks like they just replaced the existing ROM. I'm thinking of just burning a 27C128 with the original firmware and adding a switch to the CE* line. BASIC8 might be nice, but what's the point if most people don't have it? You can't release software that uses it. I'm not familiar with Servant, or the other utility ROMs. I will have to look for documentation for Servant. JiffyDOS does add a bit of functionality that I use, so not sure how useful these utility ROMs are. I was thinking GEOS would be cool to have, and I do have a set of original GEOS 2.0 disks, but again... how useful is GEOS really? Quote Link to comment Share on other sites More sharing options...
Calab Posted May 11, 2022 Author Share Posted May 11, 2022 10 hours ago, OLD CS1 said: The socket supports 32k (27C256 IIRC) and there are a plethora of expansions to go here: BASIC8, Servant 128, GEOS 128 v2, among others. There have been a few multi-ROMs over the ages which contain four or more of the various utilities. The U35 ROM is 16k, which would be a 27C128. But your JiffyDOS ROM should be switchable so the original Kernal can be used. If it is on a riser, then it likely is. Are the sockets in the C128 pin compatible with the 27C256 or 27C128? I'm seeing elsewhere that adapters are needed. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted May 11, 2022 Share Posted May 11, 2022 1 hour ago, Calab said: I was thinking GEOS would be cool to have, and I do have a set of original GEOS 2.0 disks, but again... how useful is GEOS really? That depends upon the user. I used it all trough my early college years (up to around 2002) before shifting to WordPerfect on the Amiga. 1 hour ago, Calab said: Are the sockets in the C128 pin compatible with the 27C256 or 27C128? I'm seeing elsewhere that adapters are needed. Not sure about those claims. I have had standard EPROMs in my 128s. I pulled Servant 128 out of one of the systems I picked up, on a standard EPROM. I understand the character ROM requires an adapter. Quote Link to comment Share on other sites More sharing options...
Calab Posted July 11, 2022 Author Share Posted July 11, 2022 So... I have tried out the DiskMaster ROM in my C128, but it reports that the 1541 drive is not supported. Very odd. Might be my Pi1541 though. I've just tried The Servant, but it messes with the JiffyDOS F keys. I don't find the Servant F key functions nearly as useful. If I ever get a mouse for the C128, then I might give GEOS a try. I see something called the Antigrav toolkit, but no details or downloads for it. Are there any other disk utilities that can go in U36? Basically, I'm just looking for something I can get to quickly if I need to copy files or disks in a pinch. Quote Link to comment Share on other sites More sharing options...
Calab Posted July 11, 2022 Author Share Posted July 11, 2022 Since I had nothing for U36 I burned a GEOS 128 v2 EPROM. It does not work. I just get a junk bitmap screen. This is with a GEOS C128 v2 disk mounted in my Pi1541 and 64k of VDG memory. Quote Link to comment Share on other sites More sharing options...
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