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About Krebizfan

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    Space Invader
  1. Intel had been shipping the Intellec development systems along with an assembler before any microcomputer using those chips was produced. I think all CPU designs after the mid-60s were released alongside a matching assembler. The switches weren't intended to be a primary programming interface but a bootstrap entry. Program the address of the paper tape; load the contents of the tape; jump to the start of the loaded program. Cheaper ROMs reduced the need for panel switches. Discarded teletypes were often the initial interfaces for pre-production micros which was used to produce the code that would be used to control a variation of the TV Typewriter and audio cassette deck. Colleges got rid of teletypes because it was possible to fit several glass terminals in floor space needed for each teletype.
  2. Assembly went well beyond just including a mnemonic for each instruction and having a variable as a label for a memory location. The PDP-8 assembler included many mnemonics for what would be library routines in normal syntax. The PDP-8 has very few instructions. The I/O mnemonics would direct I/O to the correct device without needing a dozen instructions to send data to the correct destination. That was back in 1965 and based on the PDP-5 assembler from 1963. Assembler concepts were established fairly early on. https://tangentsoft.com/pidp8i/wiki?name=A+Field+Guide+to+PDP-8+Assemblers
  3. The only graphic adventure from Scott Adam's for the TI-99/4A was the Return to Pirate's Island cartridge. That can be found in the collection of cartridges. The remaining titles that got reissued with graphics on other systems did not get a matching TI-99/4A graphics rerelease.
  4. The SX-64 sold around 50,000 units which was a respectable total for a late arriving portable machine especially one that didn't play into its software's strengths. It does seem clear that Commodore managed to find a color CRT for the same price as the mono CRT leading to the SX-64 selling at the same $1000 that the SX-100 was announced for. If the SX-100 had arrived $300 cheaper than the SX-64 like the original announcements suggested, the SX-100 might have found a market as a cheap portable word processor. Not exactly a huge market but millions of dollars in profit with no effort shouldn't be eschewed.
  5. I had read that Commodore had been stripping out boards from the 64GS and placing them in spare c64 cases. That process may well have cost less than $5.
  6. There were a few mentions of IBM PC BASIC but there isn't much to talk about with it. It implemented MS Disk Extended BASIC with Cassette BASIC lacking disk routines, IBM DISK BASIC having a short program adding the disk routines, and Advanced BASIC (GW-BASIC) gaining additional functions to handle the better graphics of CGA followed by modest updates for PC Jr, EGA, and for non-IBM systems, some of the better than CGA graphics cards. Comparing IBM Disk BASIC with TRS-80 Disk Basic, IBM had an advantage in terms of memory allowing for variable names that used 40 characters instead of TRS-80 only tracking the first two characters of a variable name and standardized cassette and disk routines so code would move from cassette to disk without rewriting. IBM also made a mistake by using full names when loading from cassette; TRS-80 loaded a file if the first character of the name was a match. Anyone who might have waited 30 minutes because of a typo would not be in favor of IBM's method. Coco BASIC got the graphical improvements of PC BASIC and I think a few other systems also had that added. Note the graphical routines started off on the Vector Graphics and MS picked up both the code and the programmer (Greg Whitten of GW-BASIC fame). There were a lot of secondary BASICs out there. Business BASICs were slow but very accurate with relatively good formatted print abilities. The minicomputer BASICs that fit into less than 64k made it easier to store structured data but eschewed graphics. I think there were a bunch of alternate interpreters for just the Spectrum; the total of all micro friendly BASIC interpreters may have exceeded 100.
  7. I thought the final Coco BASIC (enhanced extended Disk) was the variation on the MS interpreters with the most features. Performance is important though garbage collection is an often forgotten element of performance. Waiting 5 to 10 seconds for a BASIC word processor to catch up with the deletions in the middle of a document makes it a difficult product to use. Something that threw me off when adapting programs to various BASICs was the differences in the number of characters used to specify a variable. BASICs that only tracked a few characters in a longer variable name made it far too easy to have variable collisions. I hated Sinclair BASIC during my brief usage of a TS-1000.
  8. The Custom TRS-80 and Other Mysteries seems like a good example for its users. I have seen similar books for Spectrum, BBC Micro, and 8-bit Ataris; I think publishers were cranking out to a template plus a number of books involving reprinted magazine articles. Links to start you on your way The custom TRS-80 & other mysteries : Kitsz, Dennis Bathory, 1949- : Free Download, Borrow, and Streaming : Internet Archive https://www.brucesmith.info/interfacing-projects-for-the-bbc-micro/ Electronic Computer Projects (atariarchives.org) Circuit Cellar Magazine is perhaps a bit later than what you are looking for but the article series in Byte might be interesting. Many of the early magazines (Micro, Kilobaud, Compute) had such articles. Maybe a bit more specifics as to what is being sought. I doubt you need half a dozen different light pen examples.
  9. The 130ST made perfect sense in case prices for 256 kbit chips didn't drop the way history shows. With TOS in ROM, 128 kB might have been enough RAM to run many games leaving the more expensive large memory ST models for developers. But with 512 kB turning out to be about $10 more than 128 kB, the 130ST no longer had any utility.
  10. After market touch screens were another widespread failure. The touchscreens themselves were barely adequate for the job but because the touchscreen was not designed to match the monitor on which it would be mounted, accuracy was quite minimal. Light pens at least had the virtue of being cheap.
  11. The Tabor 3.25" floppy drive had the promise of cheap disks, had nice expansion cases for the IBM PC Jr and Apple II, and a couple of systems were planned to have Tabor drives installed. Went nowhere fast. Wasn't even selling when the remaindered products were sold at a significant discount. Phi-decks, cassette decks without the enclosure, were turned into high speed audio cassette systems with software control of all functions by several companies. All rapidly failed. The universal storage add-on that never managed to achieve its promised cost reductions or speed was bubble memory. It did survive in a few small markets where the limited capacity and low speed didn't matter but the durability did. I think the Tandy Model 100 and related systems became the main target for commercial use; difficult to sell the average computer user on a storage system that was slower than a floppy but cost about $500 for each 128k bubble memory expansion.
  12. The CNC machine might not have enough RAM but the paper tape reader I listed above could have 512K which is more than any paper tape roll could store even with some of the compressed encodings. It certainly would be possible to have the tape reader expand macros and pass the results to CNC machine.
  13. The Apple II had a good amount of business software available for it in native mode so plenty of sales were to small businesses. Apple did charge a premium for the base unit while Commodore sold the base unit at close to cost hoping that sales of peripherals would yield profits. Taking a Visicalc setup (64K, 2 drives, 80 columns), the Apple II was very competitively priced compared to the competition and sometimes cheaper; much cheaper if the educational discount applied. That was the target for IBM and if the bulk and educational discounts are considered, the 5150 sat comfortably in the same price range. IBM didn't care about the very cheapest computers; they wanted to forestall the high-end machines starting to challenge minis the way that DEC minis were encroaching on the mainframe. If a PC was going to take over parts of the AS/400 market, it was going to be from IBM not a hypothetical Apple IV. Commodore had the B128 as the enhanced business 8-bit at a high price; Atari had the planned 1450XLD to better serve businesses than the 800 though the video game crash prevented release. The Mac appealed to few at first. Sales stalled at about 250,000 units and didn't really pick up until memory was increased and desktop publishing became a thing. That was more than the other 68000 based personal computers could muster but modest in the overall scheme of things. Fortunately for Apple, Mac users liked buying software and could keep a sizable industry afloat despite the limited number of machines.
  14. Apple wasn't the most expensive. Look at Cromemco or the Xerox 820 to see how expensive business 8-bit machines in the early 80s could get. Apple set the Apple II price as high as the home user would go for while maintaining a build quality acceptable to American business. Commodore might have been cheaper but Commodore forgot to make enough profit to cover the costs of running Commodore. I think that banking 8-bit machines had a viable chance to compete with the IBM PC and other 16-bit systems until about 1985 when 256 K started becoming the floor for XT clones. It might take slightly more work to take advantage of the banking but the user probably doesn't care about the challenges faced by a programmer. It was unfortunate that some 8-bit systems* released just before and slightly after the IBM PC turned out to be badly flawed. The 8-bits could and did survive after that holding on to markets priced below the XT clones. * Apple III, Xerox 820, Commodore B-series
  15. The Apple II was nearing the design limits at the time. Apple had the Apple III as a follow-on but the Apple III had major problems freeing the IBM PC to secure the high end micro market. IIe and later models kept selling but the IBM PC was established by then. The 5100 series were not good comparisons for price since it used static RAM and had a huge store of Read Only Storage. Much more expensive but did improve performance.
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