CompuServe Thread

Jennifer, Hmm, how much memory do you currently have, and which model Rainbow(s) 100A or 100B/+? I don't have the catalog here, so I don't know part numbers but in a nutshell there are several options. If you have the 100A it came with 64K on the motherboard. You can then add either the 64K or 192K boards to it by just plugging them into the expansion port on the motherboard. The catch here is that neither of these boards are expandable, the memory ships are soldered to the board vs plug-in style. Additionally, you can only put one board or the other in the machine and not both. This would give you a system total of 128K or 256K respectively. The 100B/+ can also use either of the A boards, but it also has an additional board available that uses plug-in chips. DEC originally offerred this board in a 128K or 256K configuration and then you'd just buy additional chips to completely fill the board up. In this way you can achieve the maximum 896K of memory using the larger chips. Eventually DEC offered a Memory Adapter Board for the 100A's that allowed them to also use the B plug-in style boards. Because the A's have 64K vs the B's 128K on the motherboard, their maximum memory capacity is 832K. And then there is the RAMBOW board from Suitable Solutions, if you can find someone interested in selling one used. I'll try to track down my old DEC catalog tonight and see if I can't find the part numbers for you. However, I'm not sure where you'll find the memory. I'd recommend you get the maximum amount of memory you can. I've run Code Blue on a 256K machine and it works fine. However, if you have at least 768K of memory you can take advantage of Code Blues Video Mapping capability which can help speed up your applications, or sometimes make the difference between something working or not under Code Blue. Bill

Jennifer, Actually there's a specific answer about how much memory you need to run Code Blue for certain (actually most) IBM applications, including WordPerfect: 768K. The answer has nothing to do with the size of Code Blue but with the way most IBM PC programs write to video. Because IBM, unlike the Rainbow, had no fast video function, the only way to get fast video display in the IBM is to address it directly, as if it were ordinary RAM memory. Fortunately, IBM's video memory ends at 768K, far less than the Rainbow' s maximum of 896K on a 100B or 832K on a 100A. So when Code Blue is run with the /V switch, it reads the Rainbow's RAM in the range of the IBM's video memory, then copies the information to the Rainbow's video memory. It scans so quickly that you don't notice the difference. There are some IBM programs, usually small utilities, that don't write directly to the screen. You only need Code Blue to get these to run to emulate the IBM's BIOS calls. But larger programs generally write to IBM video memory. Although the Rainbow 100As originally came only with adapter cards with fixed amounts of memory, DEC later came out with expansion cards that allow memory to be added in rows of either 64K or 256K chips, with one card being able to take any possible combination. An adapter allows this card to fit in the 100A, and it fits into the 100B without an adapter. If you have one of these expansion cards — or can get one, with an adapter, if necessary — all you have to do is fill it up with 256K chips, and you're in business. — Carl