View source for GP0(E1h) Draw Mode

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---
title: GP0(E1h) Draw Mode
type: test
summary: Checks which bits of GP0(E1h) reach GPUSTAT and how textured polygons change them.
category: Hardware tests
info: Machine = SCPH-5501
info: Program = gpu/gp0-e1 (ps1-tests)
---

## Overview

The program writes zeros and ones to the [draw mode command GP0(E1h)](/hardware/gpu/gp0-environment/) and reads the result in [GPUSTAT](/hardware/gpu/gpustat/). It then draws textured polygons, whose texpage attribute also sets the draw mode, and checks the texture disable bit with GP1(09h) allowing and forbidding it.[^src]

## Results

The SCPH-5501 passed all 10 checks in every run.[^run]

Table: GP0(E1h) checks

| Check | Result |
| --- | --- |
| Write zeros to E1h | pass |
| Write ones to E1h | pass |
| Write ones with texture disable | pass |
| Textured polygons set the texpage bits | pass |
| Textured polygons with texture disable | pass |
| Textured polygons leave the other bits alone | pass |
| Texture disable bit ignored when not allowed | pass |
| Texture disable bit written when allowed | pass |
| Clearing the allow bit keeps the disable bit | pass |
| Clearing the allow bit clears the disable bit after a write | pass |

## Runs

### 25 September 2026

[13GE1.txt](/tests/raw/20260925T0000Z-5501a-card-main/main/13GE1.txt)

```
===== 13 GE1 GPU GP0 E1 | BIOS 19951204 System ROM Version 3.0 11/18/96 A

gpu/gp0-e1
pass - testWriteZerosToE1
pass - testWriteOnesToE1
pass - testWriteOnesToE1WithTextureDisable
pass - testTexturedPolygons
pass - testTexturedPolygonsTextureDisable
pass - testTexturedPolygonsDoesNotChangeOtherBits
pass - testTextureDisableBitIsIgnoredWhenNotAllowed
pass - testTextureDisableBitIsWrittenWhenAllowed
pass - testUnsetAllowTextureDisablePreservesBit
pass - testUnsetAllowTextureDisableClearsBitAfterWrite
Done.
```

### 27 September 2026

[13GE1.txt](/tests/raw/20260927T0000Z-5501a-card-2/main/s025/13GE1.txt)

```
===== 13 GE1 GPU GP0 E1 | BIOS 19951204 System ROM Version 3.0 11/18/96 A

gpu/gp0-e1
pass - testWriteZerosToE1
pass - testWriteOnesToE1
pass - testWriteOnesToE1WithTextureDisable
pass - testTexturedPolygons
pass - testTexturedPolygonsTextureDisable
pass - testTexturedPolygonsDoesNotChangeOtherBits
pass - testTextureDisableBitIsIgnoredWhenNotAllowed
pass - testTextureDisableBitIsWrittenWhenAllowed
pass - testUnsetAllowTextureDisablePreservesBit
pass - testUnsetAllowTextureDisableClearsBitAfterWrite
Done.
```

### 27 September 2026 run 2

[13GE1.txt](/tests/raw/20260927T0000Z-5501a-card-b/main/s035/13GE1.txt)

```
===== 13 GE1 GPU GP0 E1 | BIOS 19951204 System ROM Version 3.0 11/18/96 A

gpu/gp0-e1
pass - testWriteZerosToE1
pass - testWriteOnesToE1
pass - testWriteOnesToE1WithTextureDisable
pass - testTexturedPolygons
pass - testTexturedPolygonsTextureDisable
pass - testTexturedPolygonsDoesNotChangeOtherBits
pass - testTextureDisableBitIsIgnoredWhenNotAllowed
pass - testTextureDisableBitIsWrittenWhenAllowed
pass - testUnsetAllowTextureDisablePreservesBit
pass - testUnsetAllowTextureDisableClearsBitAfterWrite
Done.
```

### 27 September 2026 run 3

[13GE1.txt](/tests/raw/20260927T0000Z-5501a-card-g/main/13GE1.txt)

```
===== 13 GE1 GPU GP0 E1 | BIOS 19951204 System ROM Version 3.0 11/18/96 A

gpu/gp0-e1
pass - testWriteZerosToE1
pass - testWriteOnesToE1
pass - testWriteOnesToE1WithTextureDisable
pass - testTexturedPolygons
pass - testTexturedPolygonsTextureDisable
pass - testTexturedPolygonsDoesNotChangeOtherBits
pass - testTextureDisableBitIsIgnoredWhenNotAllowed
pass - testTextureDisableBitIsWrittenWhenAllowed
pass - testUnsetAllowTextureDisablePreservesBit
pass - testUnsetAllowTextureDisableClearsBitAfterWrite
Done.
```

### 27 September 2026 run 4

[13GE1.txt](/tests/raw/20260927T0000Z-5501a-card-g3/main/13GE1.txt)

```
===== 13 GE1 GPU GP0 E1 | BIOS 19951204 System ROM Version 3.0 11/18/96 A

gpu/gp0-e1
pass - testWriteZerosToE1
pass - testWriteOnesToE1
pass - testWriteOnesToE1WithTextureDisable
pass - testTexturedPolygons
pass - testTexturedPolygonsTextureDisable
pass - testTexturedPolygonsDoesNotChangeOtherBits
pass - testTextureDisableBitIsIgnoredWhenNotAllowed
pass - testTextureDisableBitIsWrittenWhenAllowed
pass - testUnsetAllowTextureDisablePreservesBit
pass - testUnsetAllowTextureDisableClearsBitAfterWrite
Done.
```

### 28 September 2026

[13GE1.txt](/tests/raw/20260928T0000Z-5501a-card-h/main/13GE1.txt)

```
===== 13 GE1 GPU GP0 E1 | BIOS 19951204 System ROM Version 3.0 11/18/96 A

gpu/gp0-e1
pass - testWriteZerosToE1
pass - testWriteOnesToE1
pass - testWriteOnesToE1WithTextureDisable
pass - testTexturedPolygons
pass - testTexturedPolygonsTextureDisable
pass - testTexturedPolygonsDoesNotChangeOtherBits
pass - testTextureDisableBitIsIgnoredWhenNotAllowed
pass - testTextureDisableBitIsWrittenWhenAllowed
pass - testUnsetAllowTextureDisablePreservesBit
pass - testUnsetAllowTextureDisableClearsBitAfterWrite
Done.
```

## References

[^src]: ps1-tests, gpu/gp0-e1. https://github.com/JaCzekanski/ps1-tests.
[^run]: SCPH-5501 output: [main/13GE1.txt](/tests/raw/20260925T0000Z-5501a-card-main/main/13GE1.txt) and the files beside it, with the other runs listed under Runs.