brad@bradley.UUCP (01/18/85)
I am looking for any public domain terminal programs for the IBMPC
Jr. I would like source and in 'C'. I am also currently trying
to get a program working on it. The only one so far is PC-TALK,
I have a program but the problem is that it seems to transmit the
characers to the port, but doen't recieve any? Also it seems to
transmit it to both com1: and com2: even though I don't have the
modem card installed. Mind my program works ok with the modem card
at 300 BAUD but I would like 1200 BAUD. In reading the IBM Jr. Tech
refernce it is set up differently then the PC's but I must be missing
something some where.
thanks
Bradley Smith UUCP: {cepu,ihnp4,noao,uiucdcs}!bradley!brad
Text Processing ARPA: cepu!bradley!brad@UCLA-LOCUS
Bradley University PH: (309) 676-7611 Ext. 446
Peoria, IL 61625kelvin@arizona.UUCP (Kelvin Nilsen) (01/21/85)
i also am working on getting a terminal emulator to work on the JR. There are several problems. The first problem it looks like you've encountered is that all of the system software migrates, depending on whether you've installed the internal modem or not. Without the modem, the serial port is COM1. With the modem, the serial port is COM2 and the modem is COM1. ... a little brain-damaged! Other problems that you'll soon encounter are that race conditions in the Jr. are even more serious than in the other PC's. The technical reference suggests "NO BACK-TO-BACK" 8250 instructions. Also, it suggests that if your program will be expected to handle keyboard and modem interrupts, then don't even try using baud rates above 1200. Finally, there is no dma in the Jr. so disk operations go much more slowly. And worse, while the disk operations are taking place, ALL OTHER INTERRUPTS ARE DISABLED. Most of the file transfer protocols are designed such that this is not a problem as long as the programmer is careful about when s/he sends an acknowledge. However, lots of programmers get a little sloppy when writing for the PC, which handles disk i/o much more intelligently. Other things to look out for are that video memory is not mapped the same as in the PC. This makes it difficult to get lots of terminal emulators to run properly. I was quite surprised to discover all of these problems, considering that earlier someone had posted such a strong endorsement of the Jr. in comparison to the Sanyo MBC 550. I've had some experience with both, and my opinion is that neither is compatible enough with the bigger family to take programs off the shelf for the PC and expect them to run. And I believe the Sanyo is more open-ended (two disk drives, up to 256K memory without expensive add ons). However, the PC Jr. will probably have the greater abundance of software suppliers. kelvin nilsen - author of VersaCom for the IBM PC