Date   
Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

cmdrcosmac
 


It's such a simple circuit. Use two of 'em!. One is set to the size and location
of the ROM. The other is set to reserve 256 bytes and addressed anywhere else
as needed. When placing the hardware, watch out for routines that scan for RAM
by writing and reading back. (As IDIOT does) Perhaps a control bit fed to the
688's enable pin, so the hardware cannot be accessed until software enables it.
 Then you run the /PQ outputs of the 688's thru a gate so either one will deselect
the RAM, and the one for the hardware can enable the chip selects of the hardware
devices, and the lowest address bits operate the register address bits of the devices.

 -Chuck

Re: MS2000 MicroDos Development System

ajparent1/kb1gmx <kb1gmx@...>
 

If the 765 is in Idle mode the LES on the drive should glow but not full brightness.
Its the 765 doing drive scan for condition change and should be observed.

765 and kin all work the same way.  

Idle phase >>> command phase >>> action(read/write/seek) >>>
status phase >>> idle phase.

NOTE if you read to many bytes in idle it thing its getting a command or
something else.

General procedure is:

Enable motors
  wait a few seconds to come up to speed
Send a recalibrate command to get to the right track
  Heads should seek to 000
  status when done should be that 000 was found
Send seek command
  heads will move to selected position.
  again status should indicate command complete and a
   readstatus should get detailed status.

All of the above can be done with what every peak and poke utility as
DMA is not needed (no data transfered).

If you get this far you have done good.  Do all testing to this point with blank media!
you want the boot media write protected when you finally get to it.

However the board has more jumpers that is reasonable and the drives 
also have a lot of jumpers including drive select.  If either of the two are
wrong insanity is a reasonable defense.

Oh, normal termination is command completed and not significant errors
indicated from the recovered status bytes.

As to addresses and further data I don't have source that makes full sense.

Allison

MS2000 MicroDos Development System

cellarcat
 

I have now built a MS2000 Microdos Development System and it is more or less running.  I wire wrapped the 18s605 CPU board and my own version of a control and display board with a couple of Scott’s breadboards, and have two 32k memory boards, and the 18s651 FDC, all plugged into a 10 slot backplane made up of two of Scott’s 5 plug units.  UT71 comes up and everything works except, wouldn’t you know it, the disk handling routines. I had a blank RCA 18S651 microboard which I populated and calibrated. The board is ridiculously complex and has enough optional connections to cause premature dementia but as far as I can tell it is properly set up and working but no luck with UT71. The FDC never issues any commands and the disk drives stay resolutely mute although the FDC is clearly running and I know the drives are OK. In fact I can output to Group 8 Out 4 and get the motor spinning and then there is an index pulse and read data. I am even using the original full height 3.5 inch 720K drives with the 40 pin edge connector. Much better made than the subsequent and smaller offspring.  My control and display board has a hardware break point and allows single stepping and I have followed the code down to the Seek routine. It seems to go astray at 85DAH when it checks for “normal termination” whatever that is. The status register returns 80H which from my reading of the u765 data sheet indicates an illegal command. I am a hardware guy and do not claim any great expertise with the software. I can generally follow it but not to the point of understanding all the ins and outs with the register contents etc. I am using the version of UT71 from Marcel’s EMMA II as that gives a correct CRC reading. I was using Herb’s version but the TEST routine comes back with the message “BAD ROM”. Anybody got any ideas because I have exhausted my own.

Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

 

This 74HC688 method would work well for memory mapped I/O or memory mapped ROM but I'm not sure if it would be helpful if you needed both.


From: "cmdrcosmac" <cmdrcosmac@...>
To: cosmacelf@groups.io
Sent: Sunday, December 1, 2019 10:40:23 AM
Subject: Re: [cosmacelf] Todd's ELF-ish to get an FDC #Homebrew #microboards


I second Mike's recommendation for the memory mapping scheme.
I am running it on my current SuperElf expander. I've got IDIOT in a 32k EEPROM,
mapped at F800-FBFF. All the rest is RAM, in an AS6C1008 RAM 128kx8
from Digikey 1450-1017-ND  $2.77. It's hooked up exactly as in Mike's drawing.
 This also makes possible an arrangement described by Tony Hill in Ipso Facto # 21.
This allows you to locate a Monitor anywhere in address space and optionally
jump to it after RESET, RUN. I did it on my Elf. RESET, GO runs at 0000.
RESET, MONITOR, GO runs at F800. I believe the tradition of placing monitors at 8000
began with RCA's reset,run-u/run-p scheme. They seem to have done it on most of their
COSMAC boxes. This was OK when RAM was in short supply, but now it's limiting.
 I've run Basic 3 under both UT62 and UT71. The serial I/O routines are at the
same addresses. The Basic I have came with UT62, from Herb's site. I believe he also
has UT71/MicroDos. I haven't found a Basic made for MicroDos. I'm looking forward
to seeing your system work. You'll be computing like it's 1984!
Best,
-Chuck

Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

cmdrcosmac
 


I second Mike's recommendation for the memory mapping scheme.
I am running it on my current SuperElf expander. I've got IDIOT in a 32k EEPROM,
mapped at F800-FBFF. All the rest is RAM, in an AS6C1008 RAM 128kx8
from Digikey 1450-1017-ND  $2.77. It's hooked up exactly as in Mike's drawing.
 This also makes possible an arrangement described by Tony Hill in Ipso Facto # 21.
This allows you to locate a Monitor anywhere in address space and optionally
jump to it after RESET, RUN. I did it on my Elf. RESET, GO runs at 0000.
RESET, MONITOR, GO runs at F800. I believe the tradition of placing monitors at 8000
began with RCA's reset,run-u/run-p scheme. They seem to have done it on most of their
COSMAC boxes. This was OK when RAM was in short supply, but now it's limiting.
 I've run Basic 3 under both UT62 and UT71. The serial I/O routines are at the
same addresses. The Basic I have came with UT62, from Herb's site. I believe he also
has UT71/MicroDos. I haven't found a Basic made for MicroDos. I'm looking forward
to seeing your system work. You'll be computing like it's 1984!
Best,
-Chuck

Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

 

A suggestion for your new memory card, if I may?  I realize it's a radical departure from your current design strategy (grin)...

Happy Holidays...  Cheerful regards, Mike, K8LH


From: "taf123" <todd.ferguson@...>
To: cosmacelf@groups.io
Sent: Sunday, December 1, 2019 3:50:37 AM
Subject: Re: [cosmacelf] Todd's ELF-ish to get an FDC #Homebrew #microboards

Hi Chuck -

One of the reasons for basing it on the RCA CDP18S651 is so I can use UT71 and RCA MircoDOS intended for the RCA MicroDisk Development System MS2000 - see RCA MPM-241.  I managed to find an original Disk for this and the associated BASIC on eBay.

I'll need to make an additional memory card to go with this as well since that system used a 2k ROM at 8000 with RAM filling the rest of the addressable space.  My ELF-ish currently only has 16K RAM and a 4k ROM at 8000.  This will require disabling the memory-mapped I/O devices I have in upper memory, but I included a jumper in the system to do allow this.

Cheers,
Todd

Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

taf123
 

Hi Chuck -

One of the reasons for basing it on the RCA CDP18S651 is so I can use UT71 and RCA MircoDOS intended for the RCA MicroDisk Development System MS2000 - see RCA MPM-241.  I managed to find an original Disk for this and the associated BASIC on eBay.

I'll need to make an additional memory card to go with this as well since that system used a 2k ROM at 8000 with RAM filling the rest of the addressable space.  My ELF-ish currently only has 16K RAM and a 4k ROM at 8000.  This will require disabling the memory-mapped I/O devices I have in upper memory, but I included a jumper in the system to do allow this.

Cheers,
Todd

Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

cmdrcosmac
 


Todd,
What operating system will you be running on this?
-Chuck

Re: Todd's ELF-ish to get an FDC #Homebrew #microboards

taf123
 

I've assembled the FDC chassis and populated all of the sockets.




And it's all labelled on the back side




Now for the "quick" job of wiring all of this...

Re: A video of my 1802 tester made from Arduino Mega

taf123
 

That's very cool - thanks for sharing.

Todd

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

ajparent1/kb1gmx <kb1gmx@...>
 

Herb,

One of the issues with groups.io in general is that most users are Email based and
this very note if left idle for a week is effectively forgotten even thought the web version
you can look back and all.  So despite a huge history of questions and answers 
the same questions will reappear and get forgotten.

Hint: there is a Wiki and its editable.  Stuff that pops up needs to be there if only
so "read the wiki" has meaning.

As to 1802 software, if there is any standards it is the lack of any, save for those that
RCA built to or suggested.    A week or so ago I whinged about old programs are often
hex only, no source.  Rather than rehash, it makes for tracking down those "special"
addresses part of the un fun work.   The end result is that While the 1802 is very
capable processor its sorta stuck in the late 70s or requires new from the ground
up development.  Same reason old ways are awkward to use with some new ways.

That's not your fault as preserving what has been done is a big deal.  However
old code has that issue that doing something new without complete context is a pain
or a bit of forensic re-engineering.

Allison

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

thinkpast
 

Ray: to your point. You are mistaken in your assumptions.

Chuck failed to post, that the user's problem was with their serial interface and how my particular Tiny BASIC plus IDIOT monitor, in the binary given, didn't happen to fit this guy's use of Lee's 1802 Membership Card. His problems were not with my flavor of "Tiny BASIC", which is the same Tom Piittman's code from RCA of decades ago. The various "version" differ, in monitor-like code and how "serial" is implemented. Ray - please take note of this description of Tiny BASIC variations.

So Chuck - you left the impression that you used your code, because my code was defective or faulty in some way. And so, Ray posts in effect "why does Herb have this nonworking version of Tiny BASIC?". That's what he implied. Ray, I'm sure Chuck used his code, because it was familiar to him; he was not obliged to use mine. The guy wanted a working Tiny BASIC, Chuck gave him one that worked - problem solved.

But pardon me, if this leaves me unhappy. The problems with COSMAC programs and computers, which use EF3 or EF4, and Q, to operate as a software serial UART,- all in different ways, on any kind of modern computer and USB/serial dongle - have been discussed many times in this discussion list. My Web pages include several on the subject. Chuck should have pointed to this as the problem, to avoid confusion about my particular version of Tiny BASIC.Those unfamiliar, can search my site and the Web and this discussion group for details.

I've added a note to my TB Web page, to point to my IDIOT monitor Web page, which discusses the issue of setting up the EF's and Q. That may help the next person who uses my TB and gets stuck. By the way: my guess that it was a RAM problem? Not a problem. Thanks to Loren Christensen for verifying that is not a problem.

I hope those who read my Web pages, get the idea that I'm trying to help them out, and provide tools and means to work with their COSMAC computers, the 1802 MC in particular. I give them means to contact me if they have problems. I am sorry the user did not contact me, but that's not his obligation to do so. But when my code is mentioned in a public forum, I feel obliged to speak up, and of course to help some user of it if I can. So pardon me again, for being unhappy that I spent time on this Thanksgiving, trying to help this user - and was left explaining how one's persons fix did not mean my code was particularly at fault. And I've learned something about giving help when I was not asked personally for help.

Regards,
Herb Johnson

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

Lee Hart
 

Raymond Sills via Groups.Io wrote:
Hi Guys:

Why is it that there are two (possibly more) versions of Tiny BASIC?
Presumably, one or more versions have deleted features or functions
deemed not worth including. I have a Tiny BASIC board for the RCA VIP,
and IIRC, it uses about 4K of ROM. I never tried looking at the
underlying hex code.
Tom Pittman's original Tiny BASIC was 2K bytes, but it did *not* include the I/O drivers. It just had three LBR's (CONIN, CONOUT, and BREAK), which you had to patch to point to your system's I/O drivers.

On an Elf with one of RCA's monitors (i.e. UT4), or a Quest or Netronics Elf with their monitors, you had to provide your own I/O routines. These vectors were then patched to jump to your routines. They would of course be different for every system, as there were no standards in those days. It might use Q and EF3 or EF4, a parallel port, an actual UART chip, an 1861 video chip, etc.

Tom provided detailed instructions for modifying Tiny BASIC. When the system had extra features (like an 1861 video chip), then people extended Tiny BASIC to add commands to control it. The RCA VIP, Netronics, and Quest Elves all did this.

You're generally going to download a "package" that comes with somebody's hardware-specific I/O routines already included. To work, your Elf needs to have the *same* hardware setup. Or, you have to change it to support the hardware you have.

Lee
--
ICEs have the same problem as lightbulbs. Why innovate and make
better ones when the current ones burn out often enough to keep
you in business? -- Hunter Cressall
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

ajparent1/kb1gmx <kb1gmx@...>
 

My archive has more than five distinctly different tiny or small basics, not 
a this is a mod of that but distinct different origins.  I also may be under
counting that.

In the early days there wer three peices of software that many tried or did.
Monitor
Basic
Assembler,
Editor

That generally applies to most all of the micros.

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

ajparent1/kb1gmx <kb1gmx@...>
 

There are many versions.

For example I have a copy of QUEST TB on paper tape meant to be loaded into ram.

So when people say tiny basic the only meaning it has it s a typically integer basic
with out strings or maybe limited strings. 

Allison

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

Raymond Sills
 

Hi Guys:

Why is it that there are two (possibly more) versions of Tiny BASIC?  Presumably, one or more versions have deleted features or functions deemed not worth including.  I have a Tiny BASIC board for the RCA VIP, and IIRC, it uses about 4K of ROM.  I never tried looking at the underlying hex code.

73 de Ray



-----Original Message-----
From: the-eagle@... <The-Eagle@...>
To: cosmacelf <cosmacelf@groups.io>
Sent: Thu, Nov 28, 2019 2:17 pm
Subject: Re: [cosmacelf] Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

Herb, read the email that I just sent you. We are not using the version of Tiny Basic that you are distributing.

Regards,
Chuck

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

thinkpast
 

Thanks for your detailed reply and help. Chuck reached out to me and I have a
working .bin file now.
Please do me and others who use this Tiny Basic a favor? Please tell me what the fix was? If you don't know, send me the fixed binary you have? My email address is available from any of my Web pages, at the bottom of each Web page. Thank you.

And Chuck - do me the same courtesy? Presumably you can explain the fix as you executed it.

As I'm distributing this version of Tiny BASIC, I am trying to provide some support and problem-solving. The version at Lee Hart's site, is a copy of my version.

Regards, Herb Johnson
retrotechnology.com

Re: An Elf called Mar1e - a little progress

John
 

Thanks Stuart, that sounds like the right reason for 9 LEDs. It's been months since I did anything with the Elf. I didn't make notes about the LEDs at the time when it was fresh in my mind, and my mind is no longer fresh!

I don't have a single-step facility or a slow-down-able clock yet. I'm tempted to preserve the Elf called Mar1e just as she is, with front panel switches, and start building new one with the hex keypad. Mar1e's board is just about full, with two DLR1414 4-character displays, TC-232, 16 address LEDs and two 24 pin sockets for RAM and EPROM. 

Out with the wire-wrap tool again!

Best regards,

John
Nottingham

On Thu, 28 Nov 2019 at 08:20, Stuart Remphrey <stu@...> wrote:
> can't remember why I chose 9 LEDs

Have a single-step or _very_ slow clock?
If so, was it for the status and related lines?
(SC0, SC1, TPA, TPB, MR, MW, N0, N1, N2 = 9)

Re: An Elf called Mar1e - a little progress

Stuart Remphrey
 

> can't remember why I chose 9 LEDs

Have a single-step or _very_ slow clock?
If so, was it for the status and related lines?
(SC0, SC1, TPA, TPB, MR, MW, N0, N1, N2 = 9)

Re: Membership Card Rev JK2 - Tiny Basic Hex file #BASIC #MembershipCard

dmatyja2002
 

Hi Herb,

Thanks for your detailed reply and help. Chuck reached out to me and I have a working .bin file now.
It was great to get all the responses and help on my questions.
It is fun to play with an 1802 again. I had a Netronics ELF kit back in the day.
The Membership card is a great kit now to pick up where I left off when I could not afford memory or fancy software like Tiny Basic :-)

Cheers,

-Dan