Jeff CBM7: Hi everyone! We'll get started in just a minute. Tonite, Dave Haynie (Animal 128) and myself Jeff Porter (Jeff CBM7) will answer (or attempt to answer) your technical questions regarding the C128 and it's peripherals.
QuestionCan you explain the internal serial buss connection on the PCB especially the DRESET circuit?
Animal 128: The DRESET circuit is used on the European C128D, to reset the internal disk drive. It does nothing on your C128. It is needed because you can't turn off the internal drive (to reset it) as easily as you could turn off an external drive, without also turning off you C128 and loosing any data you might have in the 128.
QuestionHow do I run .bas filetypes in cp/m mode .Bas is mentioned in the C128 manual as a legitimate filetype?
Jeff CBM7: This was probably an example in the manual. .BAS usually refer to BASIC programs. The filename extension can be any three letters. However, the only executable extension is .COM It was probably as basic source file.
QuestionI heard the MMU can go up 1 M. Why didn't you go up 1M on the chip
Animal 128: The MMU's register map is logically designed to support 1M of memory. The actual physical MMU you have in your C128 only supports 128K. This is because the current system cost is in many way dictated by the amount of total memory in the system. Also, an MMU capable of addressing more memory might be quite a bit more expensive to manufacture itself. An enhanced C128 like system could use an upward compatible MMU to take advantage of some or all of this 1M space.
QuestionHow do I access the RS232 while in CP/M mode?
Jeff CBM7: You can use the MEX and/or MDM7 programs to access the RS232 port in the CP/M mode of the 128. (for modems that is) If you want to "roll your own" you must get the source code from the CP/M SIG on another service (you know) or from the $20 deal in the c128 manual
QuestionCan I stack 1571's without having heating problems?
Animal 128: Disk Guru Greg Berlin doesn't recommend stacking them directly on top of one another. If you can leave about an inch space between the drives without obscuring the vents, you'll probably be much safer in the long run. (ga)
Questionwhat formats does the 1571 read?
Jeff CBM7: The 1571 will read and write both GCR and serveral MFM formats. The MFM formats include Kaypro, Osborne, Epson, IBM (but not MS-DOS), etc. (ga)
QuestionI have WordStar for the IBM and I cant get it to work on my 128 and 1571 Can you help me?
Animal 128: The C128 doesn't work with IBM MS-DOS at all. If you have an IBM CP/M version of Wordstar, then your problem is most likely that the version of Wordstar is configured only for the IBM computer. A good bet for Wordstar (and most other CP/M programs) would be buying a version for a Kaypro if a generic CP/M version (with installation programs) is not available. (eot)
QuestionJust how many 1902 monitors are there?
Jeff CBM7: There are two versions of 1902s. The first is the original made by Teknika. But because the demand was so high, we had to get a second supplier, Philips, maker of the 1902A. (eot)
QuestionI'd like to know about the 1571 disk drive. The double head action, can it be used for the C-64?
Animal 128: Yes, the 1571 can be used in double sided (1571) mode on a C64 or on a C128 in C64 mode. In order to do this, you OPEN15,8,15:PRINT#15,"U0>M1":CLOSE15 to set 1571 mode. A word of caution is in order, however. 1571 mode is incompatible with quite a few 1541 copy-protection schemes, so you may not be able to use double sided disks with every C64 application. (eot)
QuestionWhat is the difference between version six and version seven of the C128?
Jeff CBM7: Rev 6 had a slight compatibility problem with the Mach5 cartridge. We inverted the 8 MHz dot clock on the cartridge port. The first Mach5 cartridge was released after the 128 was announced. Dave Haynie found this bug. Thanks Hazy. (eot)
QuestionI noticed that reading the disk status is by just using variable ds and ds$. does this mean that we no longer need to open a command channel as the 1541?
Animal 128: That's generally true for most of the things you'd want to do in BASIC 7.0. You can get disk status, do copies, renames, etc. via BASIC commands. If you want to do more advanced disk commands like block read/write or other user functions, the command channel must be used. (eot)
QuestionAny update on mouse or RAM disk availability. Also any ideas about a 3.5 inch drive or possibly a harddisk?
Jeff CBM7: The mouse is currently shipping. We just Friday got FCC approval on the 1700/1750 Ram Expansion modules, so those should be shipping very soon (ready and waiting in our warehouse). We are looking at 3.5" disks and harddisks, but nothing official to announce at this point. (eot)
Questionwhy is the 1571 not compatible with the 1541
Animal 128: The 1571 (in 1541 mode) is as compatible as possible with the 1541. Where it misses is in a few cases where the 1541 is told to do things it can't really do. An example is one copy protection scheme we found. This scheme ended up causing a jump into areas of the 1541 processor space that contained neither RAM, ROM, nor I/O, but by luck found their way to valid instructions without first crashing the processor. The 1571 contains hardware identical to the 1541, but also contains the additional ROM and I/O necessary to do MFM and fast serial. This hardware occupies the areas previously empty on the 1541. (eot)
QuestionDoes an expansion module exist for RS-232 (Modems, Light Pens, …) just like an expansion module for cartriges?
Jeff CBM7: Not that I know of. We don't offer anothing like this. (eot)
QuestionI saw a sys once I think it was sys32800, 123,45,6? are there any others like it and is that one correct?
Animal 128: This one is correct, and its the only one in the system. Rumor has it there may be something similar in CP/M. (eot)
Jeff CBM7: Ok…this one won't be a question…. I have been getting some online mail about Commodore's future. We have sold over 1 million computer this past Christmas. Sales are very strong. We did however, close a couple of plants… One in England and one in California (costa mesa), and apparently that eat into our profits. We are doing very well however, and we would like to thank all of you for your support of our products. (eot)
QuestionWhat program do I need to enter assembly language for the Z80? SID included in the DRI offer is for the 8080, not the Z80.
Animal 128: I believe that DRI doesn't support Z-80 mnemonics at all. Which is a real shame, since as a some time Z-80 programmer I can attest to the superiority of the Z-80 op-codes over the 8080. But not to worry! There are available on MANY public, pay, and private CP/M BBS systems many versions of public-domain Z-80 mnemonic based assemblers and monitors. I personally have found a good relocating assembler, a monitor, and an intelligent disassembler. And some programs that will convert back & forth between Z-80 and 8080. (eot)
QuestionHow can a novice basic 'programmer' lear to alter a PD term prgm to autodial the 1670, add 1200 baud, (on c128)?
Jeff CBM7: The trick to sending commands to the 1670 is not to talk too fast. Remember that you are dealing with a software UART on the 64/128, and it is best to send characters out one at a time in a for-next loops. This means don't send a PRINT#2,"ATDT5551212". Instead send a FOR I=1 to 11: PRINT#2,MID$("ATDT5551212",I,1);:NEXT to send stuff out one character at a time. The problem is NOT with the modem, the problem is with the 64/128 software uart. The chips that are in the 1670 are IDENTICAL to a USRobotics Password modem. If you don't have a problem with it, you won't have a problem with the 1670. (eot)
Questionhow many computers are there in a 128
Animal 128: Well, that depends. The processors in the C128 function as a complete system, so from one point of view its only one "computer". Though physically there are two processors, an 8502 (very much like the 6510 in the C64, only faster) and the Z-80. And coupled with software, there are the three distinct modes of operation. C64 mode uses the 8502 exclusively, CP/M mode uses the Z-80 most of the time, but the 8502 for disk and some other I/O, and C128 mode, which uses the 8502 all the time, but will permit an application program to use the Z-80 in machine language (though there's little advantage to doing so). (eot)
QuestionCan the 2MHz clock be used for prg execution(Basic, etc.) as it can for sort routines and FOR-NEXT-LOOPS?
Jeff CBM7: You can use the 2MHz mode easily from BASIC. Just type: FAST But you loose your 40 column screen – the VIC is a timing HOG. To get back to 1MHz mode, type: SLOW and your 40 column screen will be active again. (eot)
QuestionWhat is the length of time for 1 machine cycle for the Z80 in CP/M mode?
Animal 128: A complete Z-80 machine cycle is either 3 or 4 Z-80 clock cycles, depending upon the type of cycle being performed (all 8502 cycles are 1 8502 clock cycle long). In the C128, the Z-80 clock runs for two 4MHz clock pulses, then stops for two 4MHz clock pulses, then goes again, yielding an effective Z-80 clock cycle of 2MHz (actually 2.02MHz). (eot)
QuestionIt appears that the 4416 ram chips are pin compatable with the 4464, can you replace the 4416's and have 64K of 8563 screen memory?
Jeff CBM7: Good Question! We'll have to try it. It might require some bit twidling in the 8563, but it should work. (eot)
QuestionHow can I modify the 1670 to allow for hardware control of auto-answer?
Jeff CBM7: The quickest hardware way to fix the auto answer feature is to go to Radio shack and buy a phone silencer cord. This will prevent it from answering on the first ring. (eot)
QuestionIs the 1572 still viable in the near fut ure or is it 'dead and gone'???
Animal 128: The official word at this time is that the 1572 is dead. (eot)
QuestionWho's idea was the SYS 32800,123,45,6?
Jeff CBM7: Fred Bowen. (eot)
QuestionWhat C-64 software does not work on 128 in C-64 mode, and WHY don't they work?
Animal 128: Personally I only know of "Rescue on Fractilis", though there may be others. They don't work due to errors in the program. What these programs do is overwrite the VIC chip, banging into the reserved registers at $D02F and $D030. While on a C64 there registers are undefined, on a C128 the control the extended keyscan and the 2MHz/Test registers, respectively. The reason they're overwritten is only that the programmer screwed up in calculating the number of bytes to write into the VIC register memory. The only other thing that won't work on a C128 in C64 mode is an attempted write to SID images. Why? There's no reason to support SID images. (eot)
QuestionIs the Hard drive any closer to reality?
Jeff CBM7: Nothing official, but we are hoping that Marshall or Rattigan will fall in love the prototype (eot).
QuestionIs it possible (in theory) to expand the memory of the 8563 80-column chip?
Animal 128: Yes. The 8563 can address 64K of memory. Its a modification you could make at home if you know how (eot).
QuestionAre the 1571 drives being modified at all because of the problems in 64 mode. (such as fastloaders, copiers, etc. that don't work in 1541 mode?)
Jeff CBM7: no. They are all the same. (eot)
CommentCongradulations over an easier to read 1571 manual versus the 1541 manual.
Jeff CBM7: thanks.
QuestionCan you give us a breakdown of the 512K expansion module. How much is allocated for BASIC text, Variable storage etc. And can it be used as a RAM Disk in both Native and CP/M modes?
Animal 128: The RAM Expansion module (should be shipping soon, we received final FCC approval) is accessed via DMA at the expansion port. It transfers memory around at 1Megabyte/second. In BASIC 7.0, the commands FETCH, STASH, and SWAP are used to transfer blocks of memory to/from the C128 main memory. While this does not directly expand BASIC text or variable space, it is quite simple in BASIC to use its extra memory. CP/M always configures the Expansion RAM as a Ram Disk. It appears as drive M:, with just about the full 512K available for storage (with the 1750 module). While the memory is not immediately available for RAMDISK in C128 mode, it is certainly possible (and at least one 3rd party developer is working on this). The Expansion Memory could also be accessed from C64 mode, though only from machine code (or PEEK and POKE). The machine interface to it is very straight-forward. (eot)
QuestionI have no compiler…but, can a prgm compiled from 7.0(128) run under 2.0(64) ?
Jeff CBM7: Probably not. I am assuming that the 7.0 compiler knows about the hardware in the 128, and thus wouldn't work in 64 mode. Something simple however, might work. I have heard that SM (a german company) has a 7.0 compiler available thru Micro-Pace in Champaign IL. (eot)
QuestionIs a European type ROM with language accents available for the C-128??
Animal 128: The European C128s use a different ROM, which contains an alternate character set with all those oomlats and accents, etc. In order to get this to work on an American version of the C128, you would need an European character ROM and you would have to change an internal jumper in the C128. The Europeans use what WE call the CAPS-LOCK key to change character fonts (it can happen under software control as long as the key is not locked down). (eof)
QuestionWhen communicating serially with a slave processor, should I isolate the two grounds or connect them?
Jeff CBM7: not sure what you are doing, but I guess I would connect them. (eot)
Questionwhat is the differences between the 1902 and the 1902a other that the green monitor switch?
Jeff CBM7: 1902 is made by Tekinka, the 1902A is made by Philips. That's it. (eot)
QuestionJust how many revisions of the 1702 monitor has there been? I have seen in ads that had 1802, 1703, etc…
Animal 128: The first monitor in that series was the 1701. The 1702 was a cost reduction of the 1701. Later came the "TED" monitor, in the grey case, which was similar to the 1702. This "TED" monitor is styled for the C16 & PLUS/4, but will work with the C128 or C64. It was called 1802 for awhile, and also CM-141 or something like that. If you can find one, they're usually a good buy (if you still want to live with only 40 columns.) (~D)
QuestionSome of the early 1902's had a switch position for analog video, although this position is disconnected, is it difficult to add the analog feature to the early 1902's. The internals appear to be identical to my 1902 (not just the case).
Jeff CBM7: It should be possible to upgrade it, but I personally do not know how to do it. We cannot recommend users going into the back of their monitors – High Voltage and Law suits follow. (eot)
QuestionHello Gentlemen! Welcome to QL! A friend of mine was telling me a few new interesting and troubling things. Commodore stock seems to of have fallen to around $3 a share last week, and there were rumors that the big C plans to drop Commodore 128 support all together and pin their hopes on the new Amiga. My question is "Is there any creedence to this allegation?" and a comment is that I hope you don't. The C-128 is, at least for the immediate future, Commodore's saving grace. Thanks!
Animal 128: I don't think our stock was ever down that low, but it did dip there a bit. But have no fear, as far as I know CBM has no plans what so ever to drop the C128 line, especially not with it selling so well. Its being supported — the RAM Expansion is expected out very soon, other things are likely to follow. I may be biased, but I think the C128 is a great machine. And so is the Amiga they're for different markets. Though I've got both at my house. (eot)
Jeff CBM7: Just one comment here from me…. We have known all along that the Amiga was going to be a little slow taking off because of the lack of software in the beginning. But the 128 has saved the day…and we have sold more than we had anticipated this past xmas. Also, believe it or not, the C64 is still a strong contender. The DEFACTO beginners machine! (eot)
Questioncan a Telco 212 Modem be used on a C64
Jeff CBM7: Never heard of it, but if you can get an RS232 connection out of it somehow, and you have a VIC1011A cartridge, it should work. (eot)
Questionis there a way to format using Kaypro or a way to read/write z-100 format for CPM
Animal 128: You could format a disk similarly to the way Kaypro or the Z-100 do by directly setting up the 1571 MFM controller for the proper TRACK/SECTOR/INTERLEAVE data. But that still might not produce a disk that the Kaypro will read. Typically, along with their format information, machines like Kaypro store some additional data that the machine uses to recognize the disk as a Kaypro disk. Thus the C128 might recognize a Kaypro format disk that the Kaypro itself would not recognize (since the C128 ignores the data that the Kaypro needs to recognize the disk). The best thing to do would be to format a blank disk on a Kaypro, unless you have access to the specific information needed on a Kaypro disk. For the Z-100 you'd probably need to set up the 1571 MFM controller to do read/writes, as its most likely a format not built into the 1571 DOS. (eot)=
QuestionJeff, I was wondering what improvements if any, will be made for the new 1670's. ?
Jeff CBM7: New 1670s aren7t scheduled to be available until later this year. Perhaps the summer, but it all depends on alot of things. We have improved the Hayes Emulation, and it will default to echo on power up and won't answer on the first ring. Everything you guys wanted. (eot)
QuestionWhen do you usually use BURST mode and what is BURST mode?
Animal 128: "BURST" mode is a special way of transmitting data between the 1571 and the C128. It is used only in specific machine applications (you get it alot in CP/M) where the data to be loaded is well defined. The BURST method is less general than the normal DOS loads, but is faster. This speed comes from less software overhead on both sides of the serial link — the actual data is always transferred at the same rate in FAST SERIAL mode. (eot)
QuestionI've found the CP/M offer to have a great deal of redundant info and difficult to interpret. Can you recommend another book on CP/M?
Jeff CBM7: Osborne has a book called the "programmers' guide to CP/M" and Rodney Zaks also has a good beginner book. (eot)
QuestionI was offered an 8in. floppy drive which has no markings on it. Would it be hard to interface it to my 128?
Jeff CBM7: It would be VERY difficult to interface this to your 128. Give it to one of your old time CP/M buddies. (eot)
QuestionWill the disk that came with my 1571 operate in 80 column mode?
Animal 128: The 1571 and the DISK you have are not dependent on video mode. Some programs are, however. Any normal graphics based programs will operate only on the 40 column display. Other programs run in FAST mode for speed and, as such, will only operate in 80 column mode. Anything written in generic BASIC can work on either screen, and many machine language programs do so as well, as the interface in the Kernal supports both very similarly. (eot)
QuestionIs the 1700 RAMdisk module so designed as to allow you to easily upgrade it to a 1750?
Jeff CBM7: Yes it is possible to upgrade the 1700 to a 1750, but it involves unsoldering 16 ram chips. Not a pleasant sight. Oh yeah, one jumper too. (eot)
Questionin the cpm mode using I get two lower case i's after every line feed is this a bug in the system or a problem with my printer interface?
Animal 128: It sounds like a bug in your printer interface. I've used ~P with the MPS 1000 printer with no adverse effects. Of course, the CBM "quote mode" is a problem in CP/M, and the " character is usually translated to ' on printouts. (eot)
QuestionCan you speed up the write time of the 1571 in CP/M mode?
Animal 128: There is a program out on various BBS systems that will do just that. It speeds up the writes by about 50% or so. The reason CP/M writes can be so slow is that the 1571 does an automatic verify after each track is written. CP/M supports its own verify, which is faster, so this 1571 verify can be turned off, speeding up writes without degrading system performance otherwise. (eot)
QuestionWhere may a user get good information on using the burst routines. i.e. an easy way to learn how to use the protocol with little or no trouble? I didn't find the examples in the DOS book to helpfull.
Jeff CBM7: Burst routines and easy are mutually exclusive terms. Maybe next month we'll be able to get one of the two disk drive doctors on the air to talk about it further….sorry. (eot)
QuestionDo you know which developers are working on programs which will use the expansion modules?
Animal 128: Definately some are. Microtechnic Solutions is supporting the RAM Expansion in Sixth Sense 128. A C128 mode Ram Disk is being done by at least one 3rd party (I don't believe they've officially announced it yet). I've also heard of a popular word processor that will use it for extra space. I don't mean to be vague, but I don't know what I can really say until a developer has officially announced a product. And when you buy the expansion CP/M can immediately use it as a RamDisk, and a disk of BASIC demos comes too. (eot)
Jeff CBM7: Well, dave and I are going for Beer and food, and they stop serving at 12 midnight so we have a half hour to get there, but I'll take one more quickie.
Questioni dont know how to have my modem auto answer i have a 1660/300 and i would also like to know if you could re ccomend where i could get a bulliten board program to make have a system of my own and if i could find one in Q-LINK
Jeff CBM7: HALs BBS I believe works with the 1660. In order to answer on the 1660, you must look at the user port, decide if it is ringing, and then go off hook, and of course have the swoitch set for answer. More details are in the appendix of the modem manual. (eot) Sorry If we cut some of you guys off… but duty is calling. Send us mail if your question did not get answered.
Animal 128: Jeff, I definately hear a BEER calling me…
Jeff CBM7: Thanks and we'll see you next month. same time same channel.
Animal 128: That's same BAT time, same BAT channel.
QuestionI also have heard the rumor that DRI has withdrawn all support from CBM. Is this true, and if so, or if it comes to pass, will Commodore support CP/M ???
Animal 128: DRI doesn't support CP/M, they only liscence it. We do the support work ourselves. (eot)
Animal 128: Bye, ALL.