mth@ihnp1.UUCP (M. Horbal) (11/15/84)
Does anyone have any information about the PC Junior ROMS? 1. Does anyone offer a programming service? 2. Are the formats public domain? 3. Can the ROMS contain BASIC programs? Also: 4. Is it possible to configure the Jr with a second (external?) floppy? 5. What are the restrictions on using the "modem" communications port, e.g. can be used with some other RS232 device? Thanks in advance ihnp4!mth or Mark Horbal (312) 979-3425 -- Mark T. Horbal IH1b230 ...ihnp4!ihnp1!mth (312) 979-3425
sdyer@bbncca.ARPA (Steve Dyer) (11/17/84)
Does anyone have any information about the PC Junior ROMS?
I'm assuming you mean the ROM cartridge paks for the PCJr.
1. Does anyone offer a programming service?
Unfortunately, most of the PCJr magazines are now defunct, but
I do remember seeing ads for a service of this type.
2. Are the formats public domain?
3. Can the ROMS contain BASIC programs?
Yes, they are. Read the PCJr Technical Reference Manual. Actually
the way the ROM paks can be used is neat: first, they can simply
contain machine code, perhaps as BIOS extensions, or they can be
associated with a file name, such that typing the name to the command
interpreter causes the program to be run, or they can contain BASIC
tokens, which can be accessed, also by file name within basic. More than
one "file" can be stored in the cartridge: the BASIC cartridge contains
most of what is considered "Advanced BASIC", under the name "BASIC", but
it also contains a simple communications BASIC program called "TERM"
(which I haven't used.)
Also:
4. Is it possible to configure the Jr with a second (external?) floppy?
Yes. I suspect that IBM simply didn't extent the drive select pins to the
cable connector, but you can purchase another functionally identical disk
controller board from Legacy Technologies which allows a second drive
to be connected. You probably want to specify a longer cable than what they
generally supply, since their cable is used with their add-on unit which
sits on top of the PCJr. If you have a drive already, and some add-on boards,
their cable won't be long enough. Two feet seems just right. By the way,
the Legacy controller fully passes IBM diagnostics--it offers nothing more
or less than the IBM controller, except for the ability to access a second
disk.
5. What are the restrictions on using the "modem" communications port,
e.g. can be used with some other RS232 device?
The serial port (COM2:) is a general purpose RS232 device, usable with an
external modem or with a serial printer. The "modem" port doesn't exist
really until you buy the IBM modem (or an equivalent) since I believe the
UART is actually on the modem board. It would be quite a trick to use it
for anything else. I don't know why, however, a card couldn't be designed
for that slot which provided another simple RS232 interface.
Let me put in another plug for the Microcom ERA2 PCJr modem, which is 1200/300
baud, and comes with a very nice comm package. The only fault I find with
it is a "not invented here" syndrome, in which they provide their proprietary
MNP link and FTP protocols, but miss 99.9% of the market by deliberately
omitting XMODEM and KERMIT. You can get around this, however, by using other
comm packages with the modem.
--
/Steve Dyer
{decvax,linus,ima,ihnp4}!bbncca!sdyer
sdyer@bbncca.ARPAmark@cbosgd.UUCP (Mark Horton) (11/18/84)
And while we're at it:
(6) How much does a ROM cartridge hold? Are there any restrictions on
what can go in it (e.g. code, read only data?)
(7) Can you double this capacity by using both slots?
(8) Where in the 1MB address space do the roms go?
(9) How do they interact with any extra RAM you install?