Ken@hou2b.UUCP (06/27/83)
Hi. Last March, I bought a H100 kit from my local Heathkit store. I posted a couple of articles then, describing my experiences in purchasing and assembling the machine. I don't have copies of those articles anymore, so if you missed them then, I'm sorry, but they were very positive. I was very pleased with the H100 then, and I still am. Recently, several people have asked how I feel about the machine after a couple of months of use. The following are some random ramblings about the H100. First, the machine still works fine. I have had no problems, except for some "WILD INTERUPT" messages, that I think I caused by trying to run a BASIC program that I downloaded over a particularily noisy telephone line. These messages dissapeared after I quit trying to patch the program. It's nice having the dual 8088/8085 CPUs in the machine. The CP/M-85 is really CP/M 2.2 running on an 8085. As far as I know, most software written for CP/M 2.2 will run on CP/M-85, if you can get it into the machine (one exception is software that requires some of the few instructions that are supported by the Z80, but not by the 8080 or 8085). My H100 will only accept CP/M diskettes in 5.25", soft sectored, Heath format. (8" disks are optional). Programs on disks in other formats will have to be downloaded through the RS232 port or converted over to this diskette format. The 8088 runs ZDOS, which is really MS-DOS. All programs written for generic MS-DOS should run on the H100. The market for generic MS-DOS is growing rapidly. Programs written specifically for the IBM-PC may or may not work. Machine language programs should work, if they do not rely on the hardware of the IBM-PC (e.g. most graphics are hardware dependent). One big problem is that IBM-PC programs written written in BASIC will only run on the H100 if they are stored in ASCII format (using the "SAVE ... ,A" option). This is apparently a bug in the BASIC interpreter. The H100 and IBM-PC both use the same version of Microsoft's BASIC, but when programs are saved in the "compressed binary" mode or the "protect" mode, they become non-portable because the H100 version of BASIC does not translate them to ASCII properly. Most characters come out OK, but the numerals and special characters get switched around, so alot of hand translation must be done to make a program work. I have not figured out what these translations are, yet. Has someone else? Note that if the program is protected, it has to be "unprotected" before you can do these hand translations. There are quite a few software houses that specialize in the Heath product line and they are starting to come out with some good H100 software. Fortunately, unlike many IBM-PC software vendors, H100 software vendors sell their products for very reasonable prices. Because of the Heath product line has traditionally had a large hobbiest (or hacker) following these companies seem to specialize in software for appications other than the wordprocessors, data base managers, and accounting stuff that you see advertised for the IBM-PC. Zenith recently published a directory of third party software that runs on the MS-DOS side of the H100. BUSS (an independent Heath newsletter) and the Heath User's Group also publish directories of vendors for Heath computers. A couple of highly recommended publications are BUSS, an independent newsletter for Heath computers and REMark, the Heath User's Group publication. There are a couple more: Sextant, a quarterly magazine from the same folks as BUSS, and H-SCOOP, that I know nothing about. If anything, these periodicals are good for looking for product announcements and advertising since alot of the Heath vendors are too small to advertise in Byte. They also sometimes provide reader supplied hints and tips on using the machines. The H100 uses VT52 cursor control escape sequences, so using the VT52 termcap should work pretty well. I have had no problem using the H100 as a terminal for my UNIX system at work. There are several cheap modem programs available for the H100, both under CP/M-85 and ZDOS. I use one called ZTERM that I bought from my Heathkit store for $20. It is put out by the Heath User's Group. ZTERM allows uploading and downloading of ASCII files with almost no error. I don't think binary files are possible, however. There is also MODEM7 and YAM, both of which should work on the H100. One Heath User's Group member recently sent a letter to REMark about a version of MODEM7 that they had configured for a Heath computer and were willing to share for only shipping and handling costs. I have a copy of a version of YAM configured for the H100, but I don't have the BDS C compiler needed to compile it, so I use ZTERM. I also have a version of YAM hacked to run under MS-DOS, but I don't have the CI C86 compiler to compile that, either. Oh, well. I am planning to but C86 soon, though. There is a version of C86 available for the H100. There is also a version of MODEM in 8088 assembler. I tried to download it and assemble it, but it didn't work. I'm not sure if this is because the program is configured for the IBM-PC or because I got some noise mixed in when I downloaded it. I fixed all the errors the assembler gave me, but it still didn't work. There is tons of public domain stuff available for the H100. One source is the Heath User's Group which sells most of their stuff for $20 (I think that it is public domain, although it dosen't explicitely say so). You can get them at Heathkit stores or by mail from Benton Harbor. Most of the $20 is for overhead. You get their catalog free for joining them. They have some interesting programs. Membership is recommended. There is also the CP/M user's group (CPMUG) and SIG/M. They really have alot of stuff. You can get catalogs from the New York Amateur Computer Club (NYACC), PO Box 106, Church St. Station, New York, NY 10008. These are really recommended. Unfortunately, because there is so much, even the catalogs are not cheap. These folks publish 7 (soon to be 8) books of directory listings and program documentation. The books contain about 200 pages each and go for $10 each, postage paid. These books describe the almost 200 diskettes in the CPMUG and SIG/M collection. One source for Heath format versions of these diskettes if Robert H. Todd, Jr., 1121 Briarwood, Bensalem, PA 19020. He sells the diskettes for $6 each. Included in this stuff is MODEM7, XMODEM, ZCPR, Adventure, several diskettes from the Pascal/Z user's group, several compilers, etc., etc. I think Kermit is supposed to be on one of the recent additions. Robert Todd is listed on the SIG/M distribution list that was recently posted to the net. There are also two sources for MS-DOS public domain software: PC/Blue and PC-SIG. NYACC sells a book on the PC/Blue collection, also $10. You can get PC/Blue diskettes from Robert Todd, also $6. PC-SIG supplies diskettes for both PC-SIG and PC/Blue. They sell a directory of these diskettes for $3. (PC Software Interest Group, 1556 Halford Ave., Suit #130D, Santa Clara, CA 95051). Diskettes from PC-SIG go for $5 each (plus postage on small orders). Note that PC/Blue appears to put out only programs that will run on generic MS-DOS, while PC-SIG stuff may only run on the IBM-PC. I have no experience with PC-SIG programs. I haven't purchased much software, yet. I have Multiplan ans ZBASIC on the 8088 and Wordstar on the 8085. I also have some utilities like JRT Pascal and Software Toolworks C/80 and miscellaneous CP/M utilities on the 8085. They all work fine. Another problem I have is that there does not appear to be an easy way to use data from the 8088 side with a program on the 8085 side. (e.g. using a C/80 program to filter a Multiplan data file). The only thing I could think of is to upload a file from MS-DOS to another computer, boot the 8085, then download the file to CP/M-85. The disk formats used by the two operating systems are different, so you can't just read the disketted in using the other CPU. I have considered stuffing the file into memory, switching control to the other CPU, and reading it out of memory, but I don't know enough about the machine to know if this is feasible. There is a company (mentioned in BUSS) that sells a program that allows you to read in MS-DOS diskettes through CP/M. This is one way to go. They do not sell the program to go the other way, however. Maybe that wouldn't be hard to write. My H100 still dosen't have color. RGB monitors aren't cheap. When I get around to it, I will buy some RAM to at least get grey-shades (these are 4164, 200 ns RAM, approx $4.75 each, and plug into the video board). I think I need 24 chips to get the full capability. Heath charges something ridiculous for these chips, but alot of companies advertise them in Byte. I don't have any boards plugged in to the expansion cage yet (except for the disk controller board) and probably will not get any for a while. I was thinking about getting a clock board, but that can wait. I have seen tons of stuff advertised, including 68000 boards. Some day. Unlike the IBM-PC, most of the interfaces are built in to the mother board or the video board, so you don't need a special expansion board for things like serial and parallel ports, video controllers, etc. Color graphics go on the video board. The only expansion boards sold by Heath are the disk controller board (included with the H100), memory boards, and (I think) hard disk controller boards. The H100 (and the assembled version, the Zenith Z100) seem to be getting quite popular. I think houxg!43421am is starting a user's group over UUCP. Contact him for more information. About a dozen colleges have arrangements with Zenith for Z100 purchases (required or otherwise) by students. Control Data chose the Z100 to sell through their computer stores. All in all, I think the H100 (or the assembled Z100) is a much better deal than the IBM-PC. It is less expensive, and you get the CP/M world and S100 bus, too. You can get most major software (word processors, data base stuff, business stuff, etc) for the H100 (although not in as many brands as for the IBM-PC, but who cares) and you also get a large variety of other, miscellaneous software vendors. For anyone who isn't afraid of a little soldering, I recommend the H100. I enjoyed putting it together, learned alot, and saved $1000 for 11 hours of assembly. If there are any questions or comments, please address them to me. Ken Lee BTL WB 1D301 x7178 hou2b!9484cbs whuxlc!wb3g!kfl } these aren't very reliable, but I am on this cbosg!cbscc!wb3g!kfl } account far more often