Micha's simple questions as a beginner with the great IMSAI

[IM-Micha]

Hello, my name is Mikel.

I've been traveling with the Commodore 8Bit world for about 35 years.

I think the IMSAI 8080 (through wargames back then, of course) is totally great. :D

I soldered it together with a lot of joy and now I want to learn a lot.

Excuse me if I ask beginners questions or if I don't know a lot of things. 

I am not an IT employee and have to learn a lot first.

My goal is later to connect the IMSAI with a real RS232 line e.g. with a C64 (which also has an RS232 interface card) in order to then use the C64 as a terminal for the IMSAI.

But there is still a long way to go.

(Unfortunately my English is not that good, I have already watched many THN # 001-THN #010 YT videos, but unfortunately I cannot always follow the English language exactly)

I also help myself with Google translation (even now while writing). But Dave is a great moderator in his YT videos ! many thanks!

I have successfully connected the IMSAI 8080ESP to a Windows10 Broser via WLAN (with 192.168.4.1/console/)

I can then also open the TTY console on the web browser.

My first question, I only have a "red" connection symbol in the window of the CRT terminal: I cannot establish a connection.

Do I have to adjust something with the SIO MAP? TTY Termianl works so far.

currently i see:

SIO1.port A = WEBTTY VARTO

SIO1.port B = VIOKBO

SIO2.port A = VART1

SIO2.port B = MODEM

I didn't put any extra jumpers on the back of the board.

Thank you for your valuable information in the future.

Hope we all have a lot of fun with the IMSAI8080 ESP

Greetings Mikel,.. thank you

[TheHighNibble]

Mikel,

• Do I have to adjust something with the SIO MAP? 

No. The default port mappings are good.

You must use the VIO ROM to activate the CRT: device. This is ROM2 by default.

Ini the startup configuration https://thehighnibble.com/imsai8080/configure/#startup-configuration-non-volatile-storage-nvs

Use a value of 

• Binary: 0000 1010 0101 0000
• Hexadecimal: 0A50
  

And this will allow you to boot CP/M with the CRT: as the console (no longer the TTY:). 

[IM-Micha]

Thanks for the answer,

YES, so the CRT display (top right) also turns green, and I can use the drives there,

But I would also like to use the drives and enter commands via TTY: and CRT: at the same time.

This is shown in the video THN # 003 - IMSAI 8080 Replica desktop UI at 4:30 minutes.

What is particularly necessary for this ??

It's also funny that when I reset the last 0A50 mode, I can't even "switch off" the IMSAI normally?

Thanks very much. Mikel

[TheHighNibble]

• But I would also like to use the drives and enter commands via TTY: and CRT: at the same time.

Now you must learn CP/M. I will provide one clue: learn about the STAT command.

• It's also funny that when I reset the last 0A50 mode, I can't even "switch off" the IMSAI normally?

I have tested this and it works for me. You must be doing something else to cause this.

[IM-Micha]

Ah yes OK. now I understand too.

The whole time I just looked at video # 3 and thought you were going to toggle something with the mouse pointer.

I would have listened better and followed the letters on the screen better.

Sorry ... I need new reading glasses.

I may not have understood the difference between a TTY display and a display on the CRT so far.

So far I thought that the CRT: is optimal for all ASCI control characters. But you showed that the Twilight on the TTY: works better.

The demo "Type GLOBE.VT" is only displayed as "Chaos" for both. ??

In the future, my idea is to operate the IMSAI without any modern PC (i.e. without Windows + Mac) and only to communicate via a terminal, or rather via Apple1 (repro) and RS232 interface.

I have to look again why switching off didn't work before, now it works

Thank you for your patience.

Mikel..

[udo....@freenet.de]

IM-Micha schrieb am Donnerstag, 5. August 2021 um 21:55:48 UTC+2:

I may not have understood the difference between a TTY display and a display on the CRT so far.

So far I thought that the CRT: is optimal for all ASCI control characters. But you showed that the Twilight on the TTY: works better.

The demo "Type GLOBE.VT" is only displayed as "Chaos" for both. ??

The TTY is a serial terminal compatible to a DEC VT-100 terminal connected to one of the serial ports.

The CRT is just a video monitor connected to a video card called VIO in the IMSAI. This

uses shared memory for the display, like later Commodore and such machines.

The screen memory starts @  F000, try poking there from BASIC.

Since this is only video logic and you don't want to poke your output into the video

memory it requires firmware, that is why you need to load a ROM that includes the

firmware. The IMSAI firmware implements the terminal sequences from LSI, like

the ADM3A terminal, which is very different from the ANSI terminal control. So

the .vt demos won't work at all.

This is also why you have two different patched versions of the WS editor, one for

ANSI terminals, one for LSI terminals.

[udo....@freenet.de]

udo....@freenet.de schrieb am Freitag, 6. August 2021 um 07:46:11 UTC+2:

This is also why you have two different patched versions of the WS editor, one for

ANSI terminals, one for LSI terminals.

Sorry, WM that is.

The WS editor of course can also be configured for VT-100 terminal as well as the

VIO video card.

 

[IM-Micha]

Oh dear Uwe ...  I still have a lot to learn, thank you very much for the information, ..

I had previously thought it was exactly the other way around.

Because actually a CRT device is "known" as a terminal, and I thought that it used to be always plugged into the RS232 interface 

and as a standard V52 / Ansi terminal.

Was there already RS232 (+ -12v) or only 5V as an interface with a real IMSAI.

Then I actually have to bother less with the CRT and can set the TTY as the "standard" display again (different ROM).

My goal: a real RS232 modem attached to the rear, and on TTY (displayed on the correct PC monitor via WEBinterface) or

connected to an Apple Replica via null modem.

many thanks Mikel

[udo....@freenet.de]

IM-Micha schrieb am Freitag, 6. August 2021 um 23:48:54 UTC+2:

Because actually a CRT device is "known" as a terminal, and I thought that it used to be always plugged into the RS232 interface 

and as a standard V52 / Ansi terminal.

CRT is short for Cathode Ray Tube, with the tube you can build a TV, a monitor or a terminal.

A terminal often uses RS-232 to connect to a computer, while a monitor needs analog video

signals provided by some computer board. Another term for a terminal is glass TTY, means

a teletype with a display made from glass, the tube.

With TTY we usually mean some sort of terminal, with CRT we mean a display monitor.

Was there already RS232 (+ -12v) or only 5V as an interface with a real IMSAI.

RS232 is specified with +-12V and the original IMSAI SIO-2 cards use that. The 5V is out of specs

and usually works only with new equipment, to interface new with old equipment you might need

some level shifter circuit to adapt the voltage.

 

Then I actually have to bother less with the CRT and can set the TTY as the "standard" display again (different ROM).

Both ROM's work fine with the serial TTY device. The VIO firmware includes a signature, if that is detected by the

BIOS it will use the CRT as default console, if not the serial TTY. Working Plug&Play done by IMSAI ca. 1976, way

before someone else came up with the term for their not working Plug&Pray stuff.

You always can switch console with the stat command if both devices are present.

[udo....@freenet.de]

I forgot something, if you want you can comment the Plug&Play in the BIOS, then it always will use the

TTY as default console regardless which ROM you use. With the VIO card in the system you'll have 4KB less

memory though, because the VIO uses F000 - FFFF.

        JNZ     BO2

        MVI     A,0FFH          ;VIO FIRMWARE FOUND, SET VIO FLAG

        STA     VIOF

        MVI     A,INITIO OR 1   ;AND SET IOBYTE CON:=CRT:

        STA     IOBYTE

        CALL    VIOINIT         ;AND INITIALIZE THE BOARD

BO2:    IN      PRINTER         ;GET STATUS PRINTER PORT, F4 IS OK

comment STA IOBYTE

You still can use stat to switch consoles if the VIO card is installed.

CP/M 3 will by default always use the TTY, but there you have much more configuration features

implemented with stat, like using multiple input and output devices and so on.