[Simh] EXT :Re: TU58 device for PDP-11s

[Johnny Billquist]

On 2015-06-26 20:10, Timothe Litt wrote:
>
> On 26-Jun-15 13:43, Hittner, David T (IS) wrote:
>>
>> What PDP-11 used TU58’s, and what controller did the drive connect to?
>>
>> Dave
>>
> 11/23, 11/44, VT103, HSC50 -- among others.

Yes.

> Host: Any RS232/423 (dumb) interface, e.g. DL(V)11, MXV11.  9600 - 38400
> BPS using a packet protocol (RSP, IIRC) with XON/XOFF flow control

RSP was the initial protocol. There were some issues with it that meant 
it had problems on loaded/slow systems, so a modified version was 
developed, called MRSP if I remember right. Very similar, though.

> The drive itself has an embedded 8085 CPU that is the real controller.
> It's not terribly smart.
>
> The protocol is roughly similar to MSCP (lighter-weight); the tape is
> block-addressable, normally the 512 byte DEC standard block, although
> there's a 128 byte record mode for dealing with buffering/comm issues.
> Normally the controller assembles 4 records to make a block.  Cartridge
> is formatted with 512 blocks of 512 bytes each (0.25 MB).

Eh? In which way would it be similar to MSCP? I can't see any relation 
at all, unless you just mean that you read and write blocks with it. But 
then again, that is true of any controller.
However, it is very simple. You can hack together a driver in almost no 
time. And, as mentioned, the hardware is just a serial port.

	Johnny

>
> http://bitsavers.trailing-edge.com/pdf/dec/dectape/tu58/ has the docs.
>
>
> This communication may not represent my employer's views,
> if any, on the matters discussed.
>
>
>> *From:*Simh [mailto:simh-bounces at trailing-edge.com] *On Behalf Of
>> *Bill Cunningham
>> *Sent:* Friday, June 26, 2015 1:14 PM
>> *To:* Hans-Ulrich Hölscher; simh at trailing-edge.com
>> *Subject:* EXT :Re: [Simh] TU58 device for PDP-11s
>>
>>     ----- Original Message -----
>>
>>     *From:*Hans-Ulrich Hölscher <mailto:hoelscher-kirchbrak at freenet.de>
>>
>>     *To:*simh at trailing-edge.com <mailto:simh at trailing-edge.com>
>>
>>     *Sent:*Friday, June 26, 2015 12:56 PM
>>
>>     *Subject:*[Simh] TU58 device for PDP-11s
>>
>>     Am I right that there is currently no TU58 device available for
>>     the PDP-11 series of computers?
>>
>>     If so, would someone be so kind as to implement it?
>>
>>     Thanks in advance to all programmers who ponder on evetually doing it!
>>
>>     Regards,
>>
>>     Ulli
>>
>>
>>     I don't know about simh, but there are several simulators out
>>     there. There is something for linux too. But it sounds like a
>>     worthy cause.
>>
>>     Bill
>>
>>
>
>
>
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-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol