# u0039 user exit

The u0039 user exit reads an absolute
disk sector. This user exit provides more information than u14a.

## Syntax

```
result = oconv(read.command, ’u39’)
```

## Description

*read.command* is a dynamic array that contains:

```
read.command<1> = drive.num, <vm>, cylinder.num, <vm>, head.num, <vm>, sector.num
```
where *drive.num* can be:

| 1 | Drive A: |
| --- | --- |
| 2 | Drive B: |
| 3 | Drive C: |
| 4 | Drive D: |

```
read.command<2> = mode, <vm>, table1, <vm>, table2, <vm>, #bytes
```
where

| mode | Possible values. |
| --- | --- |
| 1 | Convert ASCII to hexadecimal. |
| 2 | Transform and prefix character. |
| 3 | Translate and delete character. |
| 4 | Transform, prefix and drop Most Significant Bit. |
| 5 | Transform, delete and drop Most Significant Bit. |
| | Value mark. |
| table1 | Contains one or more hexadecimal characters to scan for on input. If there is more than one entry, then they are separated by subvalue marks. |
| | Value mark. |
| table2 | Contains one or more hexadecimal characters to replace the corresponding characters from table1. If there is more than one entry, then they are separated by subvalue marks. |
| #bytes | Number of bytes per sector. |

## See also

- [u014b user exit](https://d3codex.com/pickbasic-flashbasic/u014b-user-exit/)

---
Source: https://d3codex.com/pickbasic-flashbasic/u0039-user-exit/ - part of the D3Codex reference.