jmh@coyote.uucp (John Hughes) (09/12/90)
Lately I've noticed some confusion floating around here about the
Tandy 16B. So, manuals in hand, here is what I know, both from the
books and my own experience (not to mention the kindly assistance
of other 16B owners, to whom I am very grateful).
In order to keep this as short as possible, I am not going to take
up bandwidth with diagrams and such. As far as I know, the service
manuals I refer to below are still available from Radio Shack. If
you intend on keeping your 16B for a while, buy them.
If you have easily answered questions, I'll be happy to look up
what answers I can from the manuals for you on an 'as-I-have-the-
time' basis. I also have available details on things like
installing 5.25" disk drives, increasing available memory, and
upgrading the processor clock speed.
Send questions/suggestions/comments to:
coyote.UUCP
-or-
arizona!coyote!jmh
dev.null
Thank you.
------------------------------------------------------------------
Referenced Publications:
1 - TRS-80 Model 16 Service Manual
RS Catalog Number: 26-6004/5/6
2 - TRS-80 12/15 Meg Hard Disk Service Manual
RS Catalog Number: 26-4152/3/5/6
3 - User's Handbook To The TRS-80 Model II
1983, Webster Systems, Inc.; Cleveland, Ohio
4 - TRS-80 15-Meg Hard Disk Owner's Manual
RS Catalog Number: 26-4155
------------------------------------------------------------------
What the Model 16 Is, and Is Not
First off, the Model 16 is essentially an extended version of the
Model II, with the primary difference being the inclusion of the
68000 CPU for the Xenix operating system. In fact, it is possible
to upgrade a Model II to a Model 16 Xenix machine without too much
pain or strain. The Model 16 retains the Model II's Z80 processor
as an I/O handler.
The Model II represented a departure from the Model I, both in it's
software and hardware design philosophy. As reference 3 puts it:
"The Model II is not an expanded version of the Model I. It is an
entirely new computer." (p. 11) In addition to the much-beloved
TRDOS (tongue firmly in cheek as I say that..), one could also run
CP/M. Hence the 16B, with its direct ancestry to the Model II, is
not a fancy Model I or Model III, and should not be mistaken for
such.
Peripheral Devices and Enhancements
The stock 16B, right out of the box, will support up to four 8"
floppy drives. These may be either single-side or double-side.
Tandy also had some other interesting stuff available, and here is
a list from reference 1:
External Floppy Disk Expansion Bay - 1 drive and 2 drive models
External Hard Disk Unit - 12 and 15 Mbyte units
ARCNET interface system
Graphics Display Upgrade
3-port Serial Interface
I have also heard mention of a cartridge tape subsystem. It shows
up as a 'diskutil' menu selection, but I've never seen one.
16B Hard Drives
To reasonably run a 16B with the Xenix OS, one needs at least a
12Mbyte hard drive, and that will be *tight*. It is not unusual to
allocate between 2 and 4 Mbytes of drive 0 just for swap space.
Then the /bin and /etc directories take up another chunk. If you
don't plan on installing the development software (nice things like
cc, lex, and yacc) then you might get by with 12 megs, but I doubt
it. I would consider 15 megabytes to be a reasonable minimum hard
disk size for any 16B system.
There are two types of external hard drive controllers, both of
which require an interface card in the 16B. This interface is not
simply an extension of the Model I expansion bus. It is SCSI, or
something very close to it. At the hard drive end, one will find
either one of two cards: the 8x300 (old) or a Western Digital
WD1000-TB1 (new). The difference is easy to spot, the 8x300 is big,
and takes up most of the PCB shelf space in the external drive
enclosure. The WD1000 is about half that size.
Since I've never fiddled with the 8x300 card, I can't make
definitive statements about it. From the PCB layout drawings,
however, it is apparent that there are connections for up to four
ST506 MFM drives. On that basis I will assume that what one can do
with a WD1000, can also be done with the 8x300. Note that I also
cannot speak for what the different rev's of Tandy Xenix think
about these cards. I run 3.02, and have never bothered to install
the version 1.something or other that I also have (I mean, like,
why bother?).
Just to make things more confusing, there are two variations on the
outboard hard drive units, primary and secondary types. A primary
type contains the actual controller. The secondaries simply contain
a power supply and a drive. Connectors on the backs of the cabinets
allow you to easily connect everything (provided you have all the
right cables). Another interesting thing about the primary-
secondary system is that the primary will control the power
supplies of the secondaries. As a result, when you twist the
keyswitch on the primary, all secondaries connected to it will also
spring to life. See references 2 and 4 for more details about this.
Both controller card types expect to see standard ST506 MFM drives
connected to them. As with any other ST506 installation, the drive
control cable (the 34 pos. one) is daisy-chained from drive to
drive. Each drive gets a dedicated 20 pos. data cable, each of
which connects to one of the four 20-pin header connectors on the
controller card. The cables are exactly the same as those used in
your garden variety PC. If you already have a hard drive (and I'm
assuming that you do), then it isn't too difficult to figure out
where the next data cable should go.
Additional hard drives are formatted and initialized for Xenix use
with the 'diskutil' utility. Refer to your system operation manual
for details, but it's really very simple to use. With no diskettes
in the floppy drives a 16B system will attempt to boot from hd0 if
it can find it. This is also where the swap area usually goes.
The maximum size per disk drive is 8 heads and 1024 cylinders. If
you max out all four drive ports you can amass a respectable amount
of mass storage. One VERY IMPORTANT note here: try to get a list of
where the disk media defects are *before* you format the drive.
diskutil will ask for it, and I don't know if the low-level format
is capable of detecting flaws in the platter surfaces. If the drive
you have does not have the defects list taped to it, then you might
try temporarily installing the drive on a PC and running something
like Gibson's SpinRite on it. Kludgy, but it will work.
16B Floppy Drives
There has been some info circulating through the net about how one
can replace the 8" drives with more reasonable 5.25" drives. I will
be glad to mail this to you if you don't already have it.
Many of the older 16B systems (if not all) used single-sided
floppies. This translates to about 600K of storage per disk. The
newer 6000 machines used double-sided diskettes. In fact, if you
plan on installing the latest and last release of the Xenix
development system, then you will probably need double-sided
drives. I haven't seen any single-side distribution disks for this
software.
16B I/O Ports
The stock 16B comes with two serial and one parallel port. The
serial ports may be configured to operate at up to 9600 baud. The
parallel port is Tandy-standard, which means a parallel cable for
a PC will not work. I made my own cable, but I have a hunch that
the printer cable from a Model III will also suffice.
3-port serial I/O cards are available for the 16B and 6000
machines, and they run about $250 or so each. You can have up to 8
serial ports (the two standard ports plus two 3-port add-on cards).
Other Considerations
Memory size is a critical determinant in the overall speed and
response of the 16B. A machine with less than 512K will spend most
of its processing time just trying to get out of it's own way, and
you'll get to hear a hard drive start to complain about excessive
swapping. 512K is bearable, but 1 meg is a lot better. If you are
handy with a soldering iron, you might consider modifying a stock
memory card to handle 1Mb worth of RAM (I also have available the
details on how this is done, if you're interested). I would suspect
that one could also purchase additional cards.
The speed of your swap device also affects the overall throughput
of the system. Although the old Tandon drives are tough as hell,
they are also slow. Installing a fast drive will greatly enhance
your system.
Finally, bear in mind that unless you have the latest and last
release of the development software, you will not be able to do
things like handle sources that use 32-character identifiers. Which
means that a lot of newer Unix/Xenix sources will be out of your
reach, unless you want to modify the code.
Contacts
Bob Snapp is well known to 16B/6000 machine owners. He offers a
variety of services and hardware.
Bob Snapp
6962 Plainfield Road
Cincinnati, Ohio 45236
513 891 4496
compuserve 70225.155
Your local Radio Shack Computer Center can also special order
manuals and perhaps some hardware and software for you.
There are three public access/BBS systems that I'm aware of that
either run on 16B/6000 machines or have software available for
them. These are:
eskimo 206 365 5458 (16B system)
mundane 608 256 3133 (6000 system)
sir-alan 814 337 3159 (used to be a 16B)
If in doubt about 9600, log in at 8/n/1 2400 or 1200 bps. You will
see a log-in prompt with instructions. Also, the number for sir-
alan may not be valid after about the middle of September, since
the log-in bulletins say that the system is moving. I'm sure a new
number will be posted somewhere in the newsgroups.
Suggested Reading
Life With UNIX: a guide for everyone; Libes and Ressler
1989, Prentice-Hall, ISBN 0-13-536657-7
UNIX Internals; Shaw and Shaw
1987, Tab Books, ISBN 0-8306-2951-3
UNIX System Administration Handbook; Nemeth, Snyder, Seebass
1989, Prentice-Hall, ISBN 0-13-933441-6mikes@iuvax.cs.indiana.edu (michael squires) (09/13/90)
In article <1990Sep12.073838.8635@coyote.uucp> jmh@coyote.UUCP (John Hughes) writes: > >Peripheral Devices and Enhancements > The 8MB hard disk subsystem for the II/16/16B also works under XENIX and can use the Quantum 2000 hard drives. The Q2080 formats to 61MB under XENIX 3.2. The Quantum drives bolt in; line 5 of the data cable must be pulled high (from the yellow insulated connector on the write protect switch). >I have also heard mention of a cartridge tape subsystem. It shows It was distributed by Radio Ranch, and had a 20MB cartridge. The Bernouilli Box was a better backup device (works also). >16B Hard Drives >There are two types of external hard drive controllers, both of >which require an interface card in the 16B. This interface is not There were three - the 8" and two 5 1/4". The two 5 1/4" controllers seem to behave the same. >Many of the older 16B systems (if not all) used single-sided >floppies. This translates to about 600K of storage per disk. The I added double-sided Shugart 860's to a Model II with a 6000 CPU; could not copy boot tracks, but everything else worked fine. >16B I/O Ports > >3-port serial I/O cards are available for the 16B and 6000 >machines, and they run about $250 or so each. You can have up to 8 >serial ports (the two standard ports plus two 3-port add-on cards). The 3-port cards don't work well with modems; the standard ports work fine at 9600 driving a Telebit TB+. > sir-alan 814 337 3159 (used to be a 16B) It's a 386 now, but the XENIX 68K sources and binaries are still there. Bob Bownes of beowulf also has some stuff. "sir-alan" is moving on 9/15, new numbers not yet available (sigh...) I also have 50 of the graphics cards (NOS). Any interested people?
doug@letni.UUCP (Doug Davis) (09/13/90)
Just a few clarifications in an otherwise very good article. In article <1990Sep12.073838.8635@coyote.uucp> jmh@coyote.UUCP (John Hughes) writes: > >In order to keep this as short as possible, I am not going to take >up bandwidth with diagrams and such. As far as I know, the service >manuals I refer to below are still available from Radio Shack. If >you intend on keeping your 16B for a while, buy them. They are available in a limited degree from Tandy National Parts 817-870-5662, who accept M/C Visa and a few others. >What the Model 16 Is, and Is Not >Peripheral Devices and Enhancements > >The stock 16B, right out of the box, will support up to four 8" >floppy drives. These may be either single-side or double-side. >Tandy also had some other interesting stuff available, and here is >a list from reference 1: > >External Floppy Disk Expansion Bay - 1 drive and 2 drive models In single sided Model II drives you could get a cabinet with up to three drives. In the double sided model 16b/6000 drives expansion was via a 1 or two drive cabinet. >External Hard Disk Unit - 12 and 15 Mbyte units 35 and 70 Mbyte units were also sold. >ARCNET interface system Useless under Xenix... >I have also heard mention of a cartridge tape subsystem. It shows >up as a 'diskutil' menu selection, but I've never seen one. It's not a "tape" cartridge system but an IOMEGA bournelli(sp?) system with one or two, 10 or 20 meg cartridge drives. The interface board on this had a resimblence to SASI.. The rumor mill has it that Bob Snapp has developed drivers for real live SCSI style devices for use with this interface board. Unfortunatly these apparently only work with the older 3.1 Xenix. >16B Hard Drives >There are two types of external hard drive controllers, both of >which require an interface card in the 16B. This interface is not >simply an extension of the Model I expansion bus. It is SCSI, or >something very close to it. No it isn't, the only thing close to SCSI that comes out the back of the II/12/16/6000 machines is the IOMEGA interface. The expansion may look like it as some of the signals that a SCSI interface has but it ain't SCSI. Its a very uncompatable propriatary expansion interface it resembles the model I/III/IV interface in its physical charicteristcs. This interface like the IOMEGA interface was entirely driven by software. (yes, with icky timing loops and everything.) >Since I've never fiddled with the 8x300 card, I can't make >definitive statements about it. From the PCB layout drawings, >however, it is apparent that there are connections for up to four >ST506 MFM drives. On that basis I will assume that what one can do >with a WD1000, can also be done with the 8x300. Note that I also >cannot speak for what the different rev's of Tandy Xenix think >about these cards. I run 3.02, and have never bothered to install >the version 1.something or other that I also have (I mean, like, >why bother?). Almost, the ST506 interface is a REAL st506 interface, not the 421/412 that you get on a PeeCee. Be carful when interfacing drives with it, one of the signal lines is different (I forget which one) and is usually shunted to ground. >The maximum size per disk drive is 8 heads and 1024 cylinders. If >you max out all four drive ports you can amass a respectable amount >of mass storage. One VERY IMPORTANT note here: try to get a list of >where the disk media defects are *before* you format the drive. >diskutil will ask for it, and I don't know if the low-level format >is capable of detecting flaws in the platter surfaces. If the drive >you have does not have the defects list taped to it, then you might >try temporarily installing the drive on a PC and running something >like Gibson's SpinRite on it. Kludgy, but it will work. diskutil can and will detect flaws in the surface, but even it isn't 100% accurate all the time. If you don't have the error map, putting on a PeeCee and running the above mentioned program is a good idea, as well as running diskutil with full verify. >Many of the older 16B systems (if not all) used single-sided >floppies. All 16B systems were double sided, perhaps you are refering to a 16A? >16B I/O Ports >The stock 16B comes with two serial and one parallel port. The >serial ports may be configured to operate at up to 9600 baud. The >parallel port is Tandy-standard, which means a parallel cable for >a PC will not work. I made my own cable, but I have a hunch that >the printer cable from a Model III will also suffice. No a model III cable is an edge card, like a model 1 cable, neither of these will suffice. Last time I looked a 6' cable for the II/12/16/6000 machines was around 35 bucks, at Radio Shack. doug __ Doug Davis/4409 Sarazen/Mesquite Texas, 75150/214-270-9226 {texsun|lawnet|smu}!letni!doug doug@letni.lonestar.org "Be seeing you..."
billg@cs.tamu.edu (William Gunshannon) (09/13/90)
In article <13154@letni.UUCP> doug@letni.UUCP (Doug Davis) writes: > >Just a few clarifications in an otherwise very good article. > >In article <1990Sep12.073838.8635@coyote.uucp> jmh@coyote.UUCP (John Hughes) writes: >>Many of the older 16B systems (if not all) used single-sided >>floppies. >All 16B systems were double sided, perhaps you are refering to a 16A? > I have one of the first 16's to come out (before the A/B designation). It was hand delivered by Tandy and a Government Contractor in hopes of selling lots of them to Uncle Sam. From the very start the 16 had thinline DS drives. The only other drives I ever saw were the ones on the Model 2. bill
nanook@rwing.UUCP (Robert Dinse) (09/14/90)
In article <1990Sep12.073838.8635@coyote.uucp>, jmh@coyote.uucp (John Hughes) writes:
John: Hence the 16B, with its direct ancestry to the Model II, is
John: not a fancy Model I or Model III, and should not be mistaken for
John: such.
I don't think the folks that commented that the interface card inside the
model II/12/16/16B/6000 made it compatable with the external expansion
connectors on the mod III/4 were confusing the two machines. Just pointing
out that hard drives and other periphery that used that connector on the
model III/4 could also be used on the 2/12/16/16B/6000 family with that
card and appropriate software.
John: To reasonably run a 16B with the Xenix OS, one needs at least a
John: 12Mbyte hard drive, and that will be *tight*.
I know someone running with a single 8 megabyte drive. I've got one machine
that has one 70 meg and one 40 meg and that is tight. I've got another that
has two 8 megs, and for what it's being used for it is adequate.
John: There are two types of external hard drive controllers, both of
John: which require an interface card in the 16B. This interface is not
John: simply an extension of the Model I expansion bus. It is SCSI, or
John: something very close to it. At the hard drive end, one will find
John: either one of two cards: the 8x300 (old) or a Western Digital
John: WD1000-TB1 (new). The difference is easy to spot, the 8x300 is big,
John: and takes up most of the PCB shelf space in the external drive
John: enclosure. The WD1000 is about half that size.
I'm not 100% confident of this, but it was my understanding there were
three external disk controllers, two based on the 8x300, one for 8 inch
drives, another for 5-1/4 inch drives, and then a >WD1010< based controller
for 5-1/4 inch drives. The interface card in the computer makes it look
like a model III/4 expansion interface connector. The only thing the SCSI
interface card was used for, to the best of my knowledge, was the Bournelli
Box (and Bob Snapp has connected large SCSI drives to it I've been told).
John: The maximum size per disk drive is 8 heads and 1024 cylinders.
Only if you haven't changed out the WD1010 for a WD2010 and patched
diskutil to allow 2048 cylinders. Concerning media defects, I have found
the supplied maps are often for 256 byte sectors or 1024 blocks and so are
not accurate anyway. What I've done is to format, and it will pick up some
errors, then run the continuous disk read diagnostic for about a week in
the mode where it does not stop on an error. At the end of the week I
add the bad cylinders to the error table by formatting again. I find this
picks up sectors that will immediately test good but have rentitivity
problems.
John: Many of the older 16B systems (if not all) used single-sided
John: floppies.
I've seen a model 16 (not 16B) equipped with single sided drives but
I've yet to see a 16B equipped with anything but double sided thinlines.
I bought a model 16B new in 1985 (what a sucker eh?), it was equipped with
double sided drives. I've yet to get any software distributed on double
sided floppies, including 3.02.00 kernal and development system which you
say you've installed.
John: 16B I/O Ports
John: The stock 16B comes with two serial and one parallel port. The
John: serial ports may be configured to operate at up to 9600 baud.
What speeds are EXTA and EXTB?
John: Bob Snapp is well known to 16B/6000 machine owners. He offers a
John: variety of services and hardware.
For big bucks! I knew Snapp has SCSI hard drives working on these machines
so I called him. He quoted me some outrageous price for 200+ meg drives, I
asked if I could just buy the software, sure for $1600, and it wouldn't
work with 3.02.00 I was told. I still don't have a SCSI drive on my machine,
anyone with information on how to do this without becoming an amputee, I'd
appreciate it.
John: There are three public access/BBS systems that I'm aware of that
John: either run on 16B/6000 machines or have software available for
John: them. These are:
John: eskimo 206 365 5458 (16B system)
I run Eskimo North, it's been on a 6000 for a couple of years now, running
with 2 megabytes of RAM, 206-365-5458 is the last line in the hunt group,
best to use (206) 367-3837, or (206) For-Ever. 3/12/2400 baud, 24 hours.
John: mundane 608 256 3133 (6000 system)
John: sir-alan 814 337 3159 (used to be a 16B)
The sysop of Mundane is Monty Schmidt, he knows how to modify the MMU's
for more than 1-meg, might be able to save you a few bucks over Tandy.tony@jassys.UUCP (Tony Holden) (09/15/90)
In article <1990Sep12.073838.8635@coyote.uucp>, jmh@coyote.uucp (John Hughes) writes: > > Many of the older 16B systems (if not all) used single-sided > floppies. This translates to about 600K of storage per disk. The > newer 6000 machines used double-sided diskettes. In fact, if you All of the 16's and mode. 12's have double sided. Only model II's have single sided. > parallel port is Tandy-standard, which means a parallel cable for > a PC will not work. I made my own cable, but I have a hunch that > the printer cable from a Model III will also suffice. Sorry. The model III uses a card edge connector. The model II,12,16 connector has a 2? pin male connector. I started out in customer support in the "towers". When the 16's came out with Xenix it was fastest thing we had ever seen. We were in hog heaven. -- Tony Holden tony@jassys
ken@csis.dit.csiro.au (Ken Yap) (09/18/90)
In article <154@rwing.UUCP>: >I've seen a model 16 (not 16B) equipped with single sided drives but >I've yet to see a 16B equipped with anything but double sided thinlines. >I bought a model 16B new in 1985 (what a sucker eh?), it was equipped with >double sided drives. I've yet to get any software distributed on double >sided floppies, including 3.02.00 kernal and development system which you >say you've installed. Just as a note of interest, I inherited the 3.01 distribution for a 16B and 2 of the 7 diskettes are DS. However tar couldn't read them properly. Eventually I worked out that the files were on one side of the diskette so I had to use dd to throw out every other group of 16 blocks. Must have been a screwup at the disk duplicator. I wonder how the original owner managed to install the software.
nanook@rwing.UUCP (Robert Dinse) (09/19/90)
In article <58182@iuvax.cs.indiana.edu>, mikes@iuvax.cs.indiana.edu (michael squires) writes: > The 3-port cards don't work well with modems; the standard ports work fine > at 9600 driving a Telebit TB+. Mine are working fine with modems at 2400 baud, don't know about 9600 baud since I don't have any 9600 baud modems.