Computer Repair Mastery Course
8100 motherboard allows use of S-100 boards with the TRS-80 Model I. Has provision to add 4K or 16K (4K. supplied) memory w oexp. interface', plus space to add RS232 and parallel I O. 150, COD okay, add postage. Quick Printer II 125. Chuck Ballard, Box 824, Monticello, MN 55362 (612) 542-0358.
The Big 16 package creates the nucleus of a truly except bnai 16 bit S 100 system o' upgrades existing 8 D systems . ano conforms to ail EEE 696 S-10C specifications S mpty plug the following assembled and tested boards into an enc'osure with power supply and motherboard, and you're ready for pro'essiona -'evei 16 bit. 6 MHz computing The package includes
I own a Tandy 1200 HD. I want to increase memory size, and according to your answer to Adam Borin in Piecemeal Memory in the March Feedback Loop (p. 16), I can do it on the motherboard. I called my local Tandy Repair Center, and they said that the 1200 with seven slots Is expandable on the motherboard and the 1200 with five slots is not. Are they correct How do I expand my memory Also, why does my screen freeze up when I use a memory-resident program, such as Sidekick (John Cole, Fremont, CA) A. The five-slot Tandy 1200 HD cannot be expanded on the motherboard, the seven-slot version can. You can verify this by examining the Product Overview page near the front of your Tandy 1200. an Introduction and Guide booklet. It will tell you if you can expand memory on the motherboard or not. Either way, the memory section of the options chapter outlines the method to expand the memory. Your freeze-up problem might be due to an operating system ROM conflict. The...
I would like to mention a good friend whose BBS is available at (415) 689-8952. Jim Strappe Steuart has a model I, LNW expansion, a 40 track DD, two Eight Inch drives, LNW 5 8 and an AT motherboard as a ramdisk, running the Yet another BBS . He has a lot of TRS-80 programs which you may download.
While much has changed in the nation and in the world, our TRS-80's remain the same. They work, which is more than I can say for some of my fancy PC's. A couple of weeks ago, my wife's IBM clone blew up. It was just luck that she had finished her screenplay, so nothing of immediate value was lost. My own 386 is at times temperamental and refuses to allocate my 8 megs of memory correctly, causing Steven (my son) endless frustration when trying to play Ultima or Wing Commander. I probably need to replace the motherboard, but that will have to wait awhile.
Did you know the RESET button on the Model I (and a heck of a lot of other machines, including CTL-ALT-DEL on the IBM) is not a RESET at all On the Model I, the RESET button was actually wired to the NONMASKABLE INTERRUPT of the Z-80. Now you know why some lockups could not be overcome by hitting the RESET button it never was a RESET What was supposed to happen was the Z-80 would jump to a location (66D, I believe), and execute the recovery code chain which began there. But most of the code chain was in RAM, loaded there at BOOT time, and if the software bomb which locked up the machine altered any of this code, then you could not recover control with the RESET button. When such an unrecoverable lockup occurs, the only solution if you don't have a real RESET button is to turn the power off, wait awhile, and turn it on again, which of course loses everything you had in memory. To overcome this little trick, I wired an extra push button to the actual RESET line of my Z-80, and as long...
The Ultimate Computer Repair Guide
Read how to maintain and repair any desktop and laptop computer. This Ebook has articles with photos and videos that show detailed step by step pc repair and maintenance procedures. There are many links to online videos that explain how you can build, maintain, speed up, clean, and repair your computer yourself. Put the money that you were going to pay the PC Tech in your own pocket.