Its a standard 8-Bit cpu but ONLY customer specified numbering - SC67314CP - SC67118CPDS - SC67508PDS ??? (all MOTOROLA - function/pins?) read inside

Additional information:

I had success to find out the cpu type - it is a 6800, BUT with clock-on-chip and an x-tal 3,6MHz, which seems strange. I traced the address- and databuslines, the r/w-line, reset-line, Vcc and ground pins and it should be a 6800. The peripheral devices are 1x6821, 1x6840, 1x6852, but there is an AMI-chip with 40 pins and another Motorola-device with 28 pins. The Motorola-chip has 8 datalines (pin20-27) and is directly connected to one port the 6821, I think it is a 68HC53, but I have no information on this chip and can't find anything in the WWW !!! May be that there is anyon, who can provide information ? Concerning the AMI-device, I think that it is not a microprocessr peripheral device, because no data- and address-lines can be found - may be that it is something like a a AM9711 (world-chip) - strange is the fact of 40 pins !?! Maybe that anyone know what it could be. As conclusion of all it is a "Vintage 6800-based Motorola Modem board"!

Any additional informations will be appreciated. Thanks in advance

peter

"Peter Hofmann" schrieb im Newsbeitrag news:1395$441071fe$506d651c$ snipped-for-privacy@news.chello.at...

1984/85.

on

its

in

hope

I had success to find out the cpu type - it is a 6800, BUT with clock-on-chip and an x-tal 3,6MHz, which seems strange. I traced the address- and databuslines, the r/w-line, reset-line, Vcc and ground pins and it should be a 6800. The peripheral devices are 1x6821, 1x6840, 1x6852, but there is an AMI-chip with 40 pins and another Motorola-device with 28 pins. The Motorola-chip has 8 datalines (pin20-27) and is directly connected to one port the 6821, I think it is a 68HC53, but I have no information on this chip and can't find anything in the WWW !!! May be that there is anyon, who can provide information ? Concerning the AMI-device, I think that it is not a microprocessr peripheral device, because no data- and address-lines can be found - may be that it is something like a a AM9711 (world-chip) - strange is the fact of 40 pins !?! Maybe that anyone know what it could be. As conclusion of all it is a "Vintage 6800-based Motorola Modem board"!

Any additional informations will be appreciated. Thanks in advance

peter

According to my c. 1984 edition of the Motorola 8-Bit Microprocessor & Peripheral Data book, the 68HC53 is an asynchronous serial communications interface adapter--an early UART sort of a chip. Unfortunately, the data in this book is only a product preview, and appears to have some typographical (and possibly other) errors, and definitely lacks any programming details beyond some very vague generalities. It does have a programmable baud rate generator built in, and appears to be unlike the 6850 in many other regards, too.

Anyway, the pinout is something like this (bad ASCII art alert):

----_---- Vss | 1 28 | R/W CS0 | | DS /CS1 | | /IRQ /RESET | | D7 RxC | | D6 XTL1 | | D5 XTL0 | | D4 /RTS | | D3 /CTS | | D2 TxD | | A1/D1 /DTR | | A0/D0 RxD | | /DSR CS2 | | /DCD AS | 14 15 | Vcc ---------

Pins 18 and 19 are multiplexed address (register select) and data, as controlled by AS (Address Strobe) and DS (Data Strobe). Internal registers are identified as follows:

A1 A0 Write Read

0 0 Transmit Data Receive Data 0 1 Prog. Reset Status 1 0 ---- Command Register ---- 1 1 ---- Control Register ----

I guess this wasn't a very popular or successful part, as the 1988 equivalent data books don't seem to have any mention of it.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose."  --Jim Elliot

Andrew, Thanks very much for your help. Thanks for the info on the 68HC53 and the pins/functions. I am very sorry, but the chip I see on the board has the data-bus connected from pin 20 to 27 and so I must guess again what it is. The total amount are 28 pins and the case is dual in line. It is directly connected to the i/o-port of a 6821 - may be that it is a non-mpu device and functions are selected by the 8 lines, which I think that these are data-bus pins ?

Again thanks very much for your assistance and a nice weekend to you and yours peter

"Andrew Erickson" schrieb im Newsbeitrag news: snipped-for-privacy@sn-ip.vsrv-sjc.supernews.net...

and

but

pins.

to

this

who

not

can be

strange

UART

Computer architecture (6800)

The 6821 is the Peripheral Interface Adapter (PIA) - SO let's start with that

The PIA interfaces to the 6800 microprocessor with an 8-bit bidirectional data bus, three chip select lines, two register select lines, two interrupt request lines, a read/write line, an enable line and a reset line. To ensure proper operation with the 6800 rnicroprocessor, VMA should be used as an active part of the address decoding.

You should usually find the 6850 used as the Asynchronous Communication Interface Adapter (ACIA).

The ACIA contains almost all the logic required to set up an asynchronous data link between a computer and an external system.

gb

Duh ... 28 pins? Processors need memory !

Okay its a memory JEDEC device (ROM/EPROM/EEPROM)

gb

Thanks for info. I believe that this chip is a baud rate generator (mc14411??- 28pins ???) and is connected to the AMI device, which could be a uart/usart ??? The early manufactured uart/usart have 40 pins (like tms6011,mm5303 ...) ... I am only missing the parallel input/output lines ? ... let's see

peter

"gb" schrieb im Newsbeitrag news:wPOdnY snipped-for-privacy@comcast.com...

the

is.

directly

On Sun, 12 Mar 2006 13:03:00 +0100, "Peter Hofmann" put finger to keyboard and composed:

The MC14411 has 24 pins.

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.