PC99 Stage 5

Rev. 9/21/01
by Charles Good
(First published April in Micropendium)
It is hard to say enough good things about this 99/4A on a PC emulator. I have twice reviewed earlier versions. But the time you read this, stage 5 will be available. The upgrade cost to registered owners will be $9.94.
New users have to pay either $47.00 or (I think) $95.00 depending on which version you purchase. If you are not an assembly programmer then the $47.00 vaersion should be all you need.
The new version adds emulations of the Myarc 512k memory expansion card. A 1 meg AMS card, the Super Space II module, a clock card, and the OPA "son of a board" operating system. Even in todays depressed market any one of these devices for a real 99/4A system would cost you at least $50.00. With PC99 you can the equivalent of a very fancy expanded 99/4A system running at better than TI speed on your desktop or laptop PC, as long as your PC is at least a 486x66. If you have a PC, you should have PC99 on it. Then you can run all your favorite 40 column 99/4A software on your "modern" computer at home or at work.
I have my PC99 set up with the Myarc floppy disk controller controlling four DSDD "floppy drives" and the Myarc ramdisk set up as DSK5. I have Funnelweb and a bunch of useful utilities installed on the ramdisk and use the floppy drives as needed for other things. Using RXBv1005B my PC99 setup goes directly to Funnelweb as soon as I start PC99. The Mayarc ramdisk can be formatted up to 1600 sectors of ramdisk, which is how I have mine set up. Unlike the real Myarc ramdisk, the PC99 emulated ramdisk keeps its memory when you shut down PC99 and turn off your computer. In fact, if you use PC99's configure program to remove the Myarc ramdisk from your emulation (which you have to do if you want to use the AMS card) and then later add the Myarc ramdisk back in, the software you had on the Myarc ramdisk will still be there. You can also configure the Myarc memory card to use Myarc entended basic, if you already have it. The docs for this version of ectended basic are included with PC99 stage 5. Myarc XB is extra fast, but buggy, and will not run normal XB programs with inbedded assembly code or with assembly CALL LOADs. You are supposed to be able to use the Myarc memory expension card as a print spooler, but this never worked properly on a real Myarc card and thus doesn't work on PC99's emulaation. Memory in the Myarc card can be bank switched under assembly software control. Using the new PC99 debugger it is possible to examine and after the contents of each bank of Myarc card memory.
You can not use the Myarc and AMS cards at the same time, since they both include the normal 32 K memory expansion. Software you put into an emulated AMS card's memory is not retained when you shut down PC99. Very few people have a real 1 meg AMS card because of the expense of purchasing the card.
Soon every PC99 owner will own such a "card" and this may stimulate a market for AMS specific software. I have earlier reviewed some of the available software.
The clock card is not a direct emulation of any real 99/4A hardware, but it is compatible with real CorComp clock cards. The emulated clock card recognizes the PC's date and maybe also the time. You can, from basic, alter the time and date of the emulated clock card without changing the PC's clock. When I run the appointment calendar program REMIND ME under PC99 the correct date is recognized from the emulated clock card so that REMIND ME opens with the correct day of the month indicated. REMIND ME does not recognize the emulated clock card's time of day, but this is not at all important to the operation of REMIND ME.
Super Space II is emulated and can be set up with the configuration program. Super space is a bank switching system for the cartridge RAM. Very little software exists for Super space II. The only such software I know of is module dump software that lets you dump a module to disk and then run the module off of disk IF you have a Super Space cartridge. This is of little use to PC99 users. However, Super Space also lets you run software that requires a "supercart", such as some of the infocom games that were converted to 99/4A format. I recommend that you enable Super Space in your PC99 emulation and leave it permanently enabled. This does not interfere with the operation of any module or disk software and if you install the emulated EA module then you can run supercart software. Infocom games that required supercart memory did not run of previous versions of PC99 but do run on PC99 stage 5.
The SOB (son of a board) operating system is really nice, although RXB completely bypasses all its nice features. You start with a slightly modified color bar screen and when you press the "any key" to continue you get a screen that displays the modules you have on line. Using TI's "review module library" system it is possible to have several modules available in a series of menus. The SOB screen shows all of these in one menu. The SOB screen also allows you to bring up a directory of all your drives and run any EA5 software from this menu. I can get a directory of any of my four "floppy drives" as well as my Myarc ramdisk "drive".
A nice feature that was supposed to work in previous versions but didn't work well is the overlay file. This is the equivalent of the little hint strip you place above your 88/4A number keys. Several overlay files come with PC99 and you can make your own with a text editor. You can configure PC99 to display the overlay file of your choice to the right of the "TI" screen. I made a combined TI Writer/Basic overlay file for myself with I find very helpful
On a regular CRT monitor PC99's TI screen display is somewhat distorted, looking too tall and not wide enough. This distortion is not noticeable on the more rectangulaar screen of laptops. New to stage 5 is the abilly to display a more realistically proportioned TI screen, more like a real TI on a real TI 10 inch monitor.
At the top of my wish list for additional PC99 features is 80 column TI compatibility so that I can run 80 column Funnelweb. This may happen in the future, although Mike Wright makes no promises. In the configuration program that comes with you are given the options to "change CPU type" and "change VDP type". Your options for CPUs are 9900 and 9995. For VDP ykou can choose 9918A, 9938, and 9958. These "changes" have no effect in stage 5. However, in the future we may have the option of a 9995 CPU (linethe Geneve) and an 80 column display using the 9938 or 9958 VDP. I don't care about the 9995 or Geneve emulation, but it would be a big advance to be able to run exixting TI 80 column software using an emulated 9938 or 9958 VDP.
PC99 stage 5 is commercial software available only from CaDD Electronics.
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