HERO Jr
A 6808 robot with a hex keypad, speech, sonar and 2K of RAM as shipped.
Open the HERO Jr in Retro Bench- Also
- RT-1 (595-3271)
- CPU
- 6808 on a 4 MHz crystal (E = 1 MHz)
- RAM
- 2 KB (one 6116 at U203, stock); U204/U205 take 8K parts
- ROM
- Two 16K monitor ROMs (U207, U208); cartridge window U206 at $6000-$7FFF
- Video
- Red data LEDs and a green POWER LED. No display.
- Sound
- SC-01 speech (U223); sound and light sensors via ADC
- OS
- System ROM v1.6; RTC-1-8 BASIC cartridge
Chips
| Chip | Where | Role |
|---|---|---|
| MC6808 microprocessor | U201 | Main CPU. Runs the monitor, ROM and speech and motion code. No on-chip RAM. |
| MC6821 peripheral interface adapter | U214, U215 | Two 8-bit parallel ports with handshake lines. |
| MC146818A real-time clock with RAM | U213 | Clock, calendar, alarm and 50 bytes of battery-backed RAM. |
| SC-01 / SC-01A speech synthesizer | U223 | Speech. Turns six-bit phoneme codes into sound. Used on the HERO 1 speech accessory and HERO Jr. |
| 6116 2K x 8 static RAM | U203 | 2K x 8 static RAM. |
| 27128-pinout 16K x 8 ROM | U207, U208 | 16K x 8 ROM or EPROM in the JEDEC 27128 pinout. |
| ADC0831 serial 8-bit A/D converter | U306 | Light and sound sensor converter. HERO Jr U306, read serially through U215. |
| TL851CN sonar ranging control | U307 | Sonar transmit control (ranging). HERO Jr U307 on the power/sense board. |
| TL852CN sonar receiver | U308 | Sonar echo receiver and amplifier. HERO Jr U308. |
| MC6850 asynchronous comms adapter | U216 (accessory) | Asynchronous serial interface (ACIA). |
Ports and connectors
- CHARGER socket (J1, rear of head), 4-pin round power socket UNVERIFIED
- RS-232 (J2, DB-25 on the switch panel; RTA-1-3 accessory), DB-25 female
- CPU to power/sense board interconnect (P201 / P301, 25 pins), 25-pin board header (cable P201 to P301) UNVERIFIED
- Power/sense board charger connector (P307), 6-pin board header UNVERIFIED
- Power/sense board battery supply (P310), 3-pin board header UNVERIFIED
- Steering motor (P309), 6-pin board header UNVERIFIED
- Drive motor (P308), 3-pin board header UNVERIFIED
- Wheel encoder sensor A3 (P311), 6-pin board header UNVERIFIED
- Sound sensor microphone SP1 (P304), 3-pin board header UNVERIFIED
- Light sensor LDR1 (P306), 3-pin board header UNVERIFIED
- Sonar transducer A4 (P305), 3-pin board header UNVERIFIED
- CPU board charger sense (P202), 3-pin board header UNVERIFIED
- CPU board switch panel connector (P203), 10-pin board header UNVERIFIED
- CPU board remote receiver connector (P204), 8-pin board header UNVERIFIED
- Keyboard board connector (P205, 25 pins), 25-pin board header UNVERIFIED
- Speaker SP2 (P206), 3-pin board header UNVERIFIED
Power rails
| Rail | Expect | Measure at |
|---|---|---|
| Battery | About 12 V; low-battery warning below about 10 V | Low-voltage comparator U303; herojr-p310 pin 2 (switched) |
| +5 V regulated (Vcc) | +5 V awake; off in sleep except for a short wake pulse every 5 s (TM) UNVERIFIED | CPU pin 8 (VCC); herojr-p201 pins 10, 11; switching regulator U302 |
| +5 V switched (+5SW) | 5 V with Sense Enable; off otherwise | Q314 output; ADC0831 pin 8; TL851 pin 1; TL852 pin 5 |
| Vca (always on) | About 5 V whenever SW1 is ON UNVERIFIED | U209 output; RTC pin 24 (VDD) |
| -10 V | About -10 V UNVERIFIED | herojr-p201 pin 9; U219 pin 1 |
Symptoms
- Green POWER LED off after ON and RESET: check 6821 PIA
- Robot does not speak; red data LEDs flash
- Speech distorted while red LEDs flash: check SC-01A
- Drive wheel does not turn, or turns only in reverse: check 6808, 6821 PIA
- Sonar malfunction: no sound from transducer: check 6821 PIA
- Malfunction in memory circuits: check 6116, 27128 ROM
- No keyboard keys respond: check 6821 PIA
- Robot sleeps and does not wake; green LED blinks only every 5 s: check RTC