Nice find! I wasn't looking at port 4 data since I assumed it was all
address outputs, but P43, P44, P45 are configured as inputs on the TPDD2
(not on the TPPD1).
;Port4.B0 I/O Pin37 P40 A8
;Port4.B1 I/O Pin36 P41 A9
;Port4.B2 I/O Pin35 P42 A10
;Port4.B3 Input Pin32 P43 A11 E1 *Config jumper pulled hi
;Port4.B4 Input Pin31 P44 A12 E2 *Config jumper pulled hi
;Port4.B5 Input Pin30 P45 A13 E3 *Config jumper pulled hi
;Port4.B6 I/O Pin29 P46 A14 *CS1 on CPLD
;Port4.B7 I/O Pin28 P47 A15 *CS0 on CPLD
I've renamed the variable from '(RAM_INT)SerDatTX_2' to
'(RAM_INT)PCB_ConfigSwitchesE1E2E3' this makes more sense.
I see in the code (F1FE to F210) the firmware is looking at E3 to
determine while transmitting data to the serial port if it should use
hardware flow control or XON (0x11) / XOFF (0x13), and then reads the
serial data looking for an XON or XOFF byte.
E1 = ??
E2 = ??
E3 = Flow control - open is hardware, closed is software.
Another TPDD2 secret discovered! I'll do some more documenting in the
code and update my GitHub tonight.
Daren Clark
On 1/28/24 08:48, Stephen Adolph wrote:
I'll add some info from your nicely documented code.
* A13 value is tested at 0xF1FE, and controls a branch to 0xF1EB;
seems to change the way serial data is transmitted. hardware default
is to branch.
* A12 value is tested at 0xF071, not sure what it does yet. hardware
default is to branch.
* A11 value is tested at 0xFF48, seems to change hardware interrupt
handling. hardware default is to branch.
On Sun, Jan 28, 2024 at 8:31 AM Stephen Adolph <twospru...@gmail.com>
wrote:
Darren, another question,
There are some inputs on pins 30,31,32 (called A13, A12, A11) that
correspond to P45, P44, P43 on the HD6301.
Port 4 of the HD6301 is hooked up to pins 73.36,35,32,32,30,29,28
for P40-P47.
I'll go look at the code, but these 3 inputs are configurable. I
wonder what they do?
Steve
On Sun, Jan 28, 2024 at 8:21 AM Stephen Adolph
<twospru...@gmail.com> wrote:
Thanks Darren.
Now that we have the real tpdd firmware I wonder what we can
do with it. Some of those variables look tempting, like side
and # of tracks.
Another question.. it looks like was there a second
unpopulated serial port on the drive? Anything in the code on
that?
P7 is unpopulated and not in the schematic, but it is there.
Steve
