6

These pages wos and timex.comboios.info suggest the fire button of the Timex TC/TS 2068 joystick is read at bit 4.

Input:

  bit D0:     up (0=active)
  bit D1:     down
  bit D2:     left
  bit D3:     right
  bit D4:     fire (0=active)
  bits D5-D7: last values sent to these bits

However looking at the schematics of the TS 2068 technical manual, it seems to be bit 7.

Am I wrong?

joystick controller

4 Answers 4

9

Androids Timex cartridge game disassembled machine code using bit 7, for checking the Timex joystick 1 0x1F6 port for the fire button:

    ld a,00eh
    out (0f5h),a
    ld a,001h
    in a,(0f6h)
    bit 7,a           <-------
    ret nz 

Pinball Timex cartridge game disassembled machine code using bit 7, for checking the Timex joystick 1 0x1F6 port for the fire button:

    ld a,00eh
    out (0f5h),a
    ld a,001h
    in a,(0f6h)
    bit 7,a           <-------
    jr z,$+15

Bit 7 surely is not an "unused" bit, it is the button/fire.

Interestingly enough, this also means the Timex 2068 "joystick controller" is not that "proprietary", but is using the Fuller standard internally/from the application point of view.

Also from the TS2068 Technical Manual, page 46, we can confirm the fire button it is indeed I/O port bit 7.

Table 2.4.4-1
Joystick Connectory Signal Assignment

Pin # Signal Name I/O Port Bit Function
1 *DIR1 0 STICK UP
2 *DIR1 1 STICK DOWN
3 *DIR1 2 STICK LEFT
4 *DIR1 3 STICK RIGHT
5 not used
6 *BUTTON 7 PUSH BUTTON
7 +5V 5 VOLT POWER
8 *READ_STB ADDRESS BIT 8 or 9*
9 GND POWER GROUND

* When Address Bit 8 is high, the READ strobe to the left joystick is driven low.
When address Bit 9 is high, the READ strobe to the right joystick is driven low.

From the Timex/Sinclair 2068 Third Party Software Guide, page 3-5:

The joysticks used are industry-standard. They connect to a 9-pin "D-type" connector.

The byte read is interpreted as follows:

1  D0:                0 indicates stick up
2  D1:                0 indicates stick down
4  D2:                0 indicates stick left
8  D3:                0 indicates stick right
16–64 (D4, D5, D6):   Not used (all ones)
128  D7:              0 indicates pushbutton depressed
2
  • I have taken the Third party Software Guide URL from one of the other answers, due to the low quality of the answers. Thanks, though. Oct 18, 2022 at 17:55
  • If this is the answer you want, then change the question to match the answer. Your question simply asked if you have interpreted the material with conflicting information correctly, you never asked which bit is the correct bit for fire button.
    – Justme
    Oct 18, 2022 at 20:28
7

You are reading it right. The schematics do not match the description.

7

According to the Timex/Sinclair 2068 Third Party Software Guide, it’s D7. 0 indicates the button has been pushed.

Also, here's the Timex tech manual (from Timex).

1
-1

Here's the Timex tech manual (from Timex): https://archive.org/details/TimexSinclair2068Manuals/Timex%20Sinclair%202068%20Technical%20Manual%20%28best%29/

And their Third Party Software Guide: https://archive.org/details/timex-computer-corp/Timex%20Sinclair%202068%20Third%20Party%20Software%20Guide/

1
  • 2
    Please edit the former answer and do not create new users. Oct 17, 2022 at 19:17

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